Made function arguments const where relevant.

Change-Id: I5b196b57976c8c718b079336a805188ccb03ef4b

14 files changed, 257 insertions, 257 deletions

diff --git a/include/compression/bwlzh.h b/include/compression/bwlzh.h
index 70d586a..ce08f69 100644
--- a/include/compression/bwlzh.h
+++ b/include/compression/bwlzh.h
@@ -17,28 +17,28 @@
    allocated to be able to hold worst case. You can obtain this length
    conveniently by calling comp_get_buflen()
 */
-void DECLSPECDLLEXPORT bwlzh_compress(unsigned int *vals, int nvals,
+void DECLSPECDLLEXPORT bwlzh_compress(unsigned int *vals, const int nvals,
 		  unsigned char *output, int *output_len);
 
-void DECLSPECDLLEXPORT bwlzh_compress_no_lz77(unsigned int *vals, int nvals,
+void DECLSPECDLLEXPORT bwlzh_compress_no_lz77(unsigned int *vals, const int nvals,
 		  unsigned char *output, int *output_len);
 
-int DECLSPECDLLEXPORT bwlzh_get_buflen(int nvals);
+int DECLSPECDLLEXPORT bwlzh_get_buflen(const int nvals);
 
-void DECLSPECDLLEXPORT bwlzh_decompress(unsigned char *input, int nvals,
+void DECLSPECDLLEXPORT bwlzh_decompress(unsigned char *input, const int nvals,
 		    unsigned int *vals);
 
 
 /* The routines below are mostly useful for testing, and for internal
    use by the library. */
 
-void DECLSPECDLLEXPORT bwlzh_compress_verbose(unsigned int *vals, int nvals,
+void DECLSPECDLLEXPORT bwlzh_compress_verbose(unsigned int *vals, const int nvals,
 			  unsigned char *output, int *output_len);
 
-void DECLSPECDLLEXPORT bwlzh_compress_no_lz77_verbose(unsigned int *vals, int nvals,
+void DECLSPECDLLEXPORT bwlzh_compress_no_lz77_verbose(unsigned int *vals, const int nvals,
 		  unsigned char *output, int *output_len);
 
-void DECLSPECDLLEXPORT bwlzh_decompress_verbose(unsigned char *input, int nvals,
+void DECLSPECDLLEXPORT bwlzh_decompress_verbose(unsigned char *input, const int nvals,
 			    unsigned int *vals);
 
 /* Compress the integers (positive, small integers are preferable)
@@ -47,12 +47,12 @@ void DECLSPECDLLEXPORT bwlzh_decompress_verbose(unsigned char *input, int nvals,
    to be able to hold worst case. You can obtain this length
    conveniently by calling comp_huff_buflen()
 */
-void Ptngc_comp_huff_compress(unsigned int *vals, int nvals,
+void Ptngc_comp_huff_compress(unsigned int *vals, const int nvals,
 			unsigned char *huffman, int *huffman_len);
 
-int Ptngc_comp_huff_buflen(int nvals);
+int Ptngc_comp_huff_buflen(const int nvals);
 
-void Ptngc_comp_huff_decompress(unsigned char *huffman, int huffman_len,
+void Ptngc_comp_huff_decompress(unsigned char *huffman, const int huffman_len,
 			  unsigned int *vals);
 
 
@@ -62,11 +62,11 @@ void Ptngc_comp_huff_compress_verbose(unsigned int *vals, int nvals,
 				unsigned char *huffman, int *huffman_len,
 				int *huffdatalen,
 				int *huffman_lengths,int *chosen_algo,
-				int isvals16);
+				const int isvals16);
 
 #define N_HUFFMAN_ALGO 3
-char *Ptngc_comp_get_huff_algo_name(int algo);
-char *Ptngc_comp_get_algo_name(int algo);
+char *Ptngc_comp_get_huff_algo_name(const int algo);
+char *Ptngc_comp_get_algo_name(const int algo);
 
 
 #endif
diff --git a/include/compression/bwt.h b/include/compression/bwt.h
index 9f927f8..fedfc3d 100644
--- a/include/compression/bwt.h
+++ b/include/compression/bwt.h
@@ -12,15 +12,15 @@
 #ifndef BWT_H
 #define BWT_H
 
-void Ptngc_comp_to_bwt(unsigned int *vals, int nvals,
+void Ptngc_comp_to_bwt(unsigned int *vals, const int nvals,
 		 unsigned int *output, int *index);
 
-void Ptngc_comp_from_bwt(unsigned int *input, int nvals, int index,
+void Ptngc_comp_from_bwt(unsigned int *input, const int nvals, int index,
 		   unsigned int *vals);
 
-void Ptngc_bwt_merge_sort_inner(int *indices, int nvals,unsigned int *vals,
-			  int start, int end,
-			  unsigned int *nrepeat,
-			  int *workarray);
+void Ptngc_bwt_merge_sort_inner(int *indices, const int nvals, unsigned int *vals,
+                                const int start, const int end,
+                                unsigned int *nrepeat,
+                                int *workarray);
 
 #endif
diff --git a/include/compression/coder.h b/include/compression/coder.h
index 34b56c1..d714c82 100644
--- a/include/compression/coder.h
+++ b/include/compression/coder.h
@@ -29,10 +29,10 @@ struct coder
 
 struct coder DECLSPECDLLEXPORT *Ptngc_coder_init(void);
 void DECLSPECDLLEXPORT Ptngc_coder_deinit(struct coder *coder);
-unsigned char DECLSPECDLLEXPORT *Ptngc_pack_array(struct coder *coder,int *input, int *length, int coding, int coding_parameter, int natoms, int speed);
-int DECLSPECDLLEXPORT Ptngc_unpack_array(struct coder *coder,unsigned char *packed,int *output, int length, int coding, int coding_parameter, int natoms);
+unsigned char DECLSPECDLLEXPORT *Ptngc_pack_array(struct coder *coder,int *input, int *length, const int coding, const int coding_parameter, const int natoms, const int speed);
+int DECLSPECDLLEXPORT Ptngc_unpack_array(struct coder *coder,unsigned char *packed,int *output, const int length, const int coding, const int coding_parameter, const int natoms);
 unsigned char DECLSPECDLLEXPORT *Ptngc_pack_array_xtc2(struct coder *coder,int *input, int *length);
-int DECLSPECDLLEXPORT Ptngc_unpack_array_xtc2(struct coder *coder,unsigned char *packed,int *output, int length);
+int DECLSPECDLLEXPORT Ptngc_unpack_array_xtc2(struct coder *coder, unsigned char *packed, int *output, const int length);
 unsigned char DECLSPECDLLEXPORT *Ptngc_pack_array_xtc3(int *input, int *length, int natoms, int speed);
 int DECLSPECDLLEXPORT Ptngc_unpack_array_xtc3(unsigned char *packed,int *output, int length, int natoms);
 
@@ -40,7 +40,7 @@ void DECLSPECDLLEXPORT Ptngc_out8bits(struct coder *coder, unsigned char **outpu
 void DECLSPECDLLEXPORT Ptngc_pack_flush(struct coder *coder,unsigned char **output);
 void DECLSPECDLLEXPORT Ptngc_write_pattern(struct coder *coder,unsigned int pattern, int nbits, unsigned char **output);
 
-void DECLSPECDLLEXPORT Ptngc_writebits(struct coder *coder,unsigned int value,int nbits, unsigned char **output_ptr);
+void DECLSPECDLLEXPORT Ptngc_writebits(struct coder *coder, unsigned int value, const int nbits, unsigned char **output_ptr);
 void DECLSPECDLLEXPORT Ptngc_write32bits(struct coder *coder,unsigned int value,int nbits, unsigned char **output_ptr);
 void DECLSPECDLLEXPORT Ptngc_writemanybits(struct coder *coder,unsigned char *value,int nbits, unsigned char **output_ptr);
 
diff --git a/include/compression/dict.h b/include/compression/dict.h
index d66dd23..26eed27 100644
--- a/include/compression/dict.h
+++ b/include/compression/dict.h
@@ -14,7 +14,7 @@
 
 void Ptngc_comp_canonical_dict(unsigned int *dict, int *ndict);
 
-void Ptngc_comp_make_dict_hist(unsigned int *vals, int nvals,
+void Ptngc_comp_make_dict_hist(unsigned int *vals, const int nvals,
 			 unsigned int *dict, int *ndict,
 			 unsigned int *hist);
 
diff --git a/include/compression/fixpoint.h b/include/compression/fixpoint.h
index 6be7482..7b6a667 100644
--- a/include/compression/fixpoint.h
+++ b/include/compression/fixpoint.h
@@ -17,16 +17,16 @@
 typedef unsigned long fix_t;
 
 /* Positive double to 32 bit fixed point value */
-fix_t Ptngc_ud_to_fix_t(double d,double max);
+fix_t Ptngc_ud_to_fix_t(double d, const double max);
 
 /* double to signed 32 bit fixed point value */
-fix_t Ptngc_d_to_fix_t(double d,double max);
+fix_t Ptngc_d_to_fix_t(double d, const double max);
 
 /* 32 bit fixed point value to positive double */
-double Ptngc_fix_t_to_ud(fix_t f, double max);
+double Ptngc_fix_t_to_ud(fix_t f, const double max);
 
 /* signed 32 bit fixed point value to double */
-double Ptngc_fix_t_to_d(fix_t f, double max);
+double Ptngc_fix_t_to_d(fix_t f, const double max);
 
 /* Convert a floating point variable to two 32 bit integers with range
    -2.1e9 to 2.1e9 and precision to somewhere around 1e-9. */
diff --git a/include/compression/huffman.h b/include/compression/huffman.h
index 49347de..f2ce187 100644
--- a/include/compression/huffman.h
+++ b/include/compression/huffman.h
@@ -12,8 +12,8 @@
 #ifndef HUFFMAN_H
 #define HUFFMAN_H
 
-void Ptngc_comp_conv_to_huffman(unsigned int *vals, int nvals,
-			  unsigned int *dict, int ndict,
+void Ptngc_comp_conv_to_huffman(unsigned int *vals, const int nvals,
+			  unsigned int *dict, const int ndict,
 			  unsigned int *prob,
 			  unsigned char *huffman,
 			  int *huffman_len,
@@ -23,11 +23,11 @@ void Ptngc_comp_conv_to_huffman(unsigned int *vals, int nvals,
 			  int *huffman_dict_unpackedlen);
 
 void Ptngc_comp_conv_from_huffman(unsigned char *huffman,
-			    unsigned int *vals, int nvals,
-			    int ndict,
+			    unsigned int *vals, const int nvals,
+			    const int ndict,
 			    unsigned char *huffman_dict,
-			    int huffman_dictlen,
+			    const int huffman_dictlen,
 			    unsigned int *huffman_dict_unpacked,
-			    int huffman_dict_unpackedlen);
+			    const int huffman_dict_unpackedlen);
 
 #endif
diff --git a/include/compression/lz77.h b/include/compression/lz77.h
index ad37e5b..d4a4beb 100644
--- a/include/compression/lz77.h
+++ b/include/compression/lz77.h
@@ -12,14 +12,14 @@
 #ifndef LZ77_H
 #define LZ77_H
 
-void Ptngc_comp_to_lz77(unsigned int *vals, int nvals,
+void Ptngc_comp_to_lz77(unsigned int *vals, const int nvals,
 		  unsigned int *data, int *ndata,
 		  unsigned int *len, int *nlens,
 		  unsigned int *offsets, int *noffsets);
 
-void Ptngc_comp_from_lz77(unsigned int *data, int ndata,
-		    unsigned int *len, int nlens,
-		    unsigned int *offsets, int noffsets,
-		    unsigned int *vals, int nvals);
+void Ptngc_comp_from_lz77(unsigned int *data, const int ndata,
+		    unsigned int *len, const int nlens,
+		    unsigned int *offsets, const int noffsets,
+		    unsigned int *vals, const int nvals);
 
 #endif
diff --git a/include/compression/merge_sort.h b/include/compression/merge_sort.h
index 48ab410..f8aaeb7 100644
--- a/include/compression/merge_sort.h
+++ b/include/compression/merge_sort.h
@@ -12,7 +12,7 @@
 #ifndef MERGE_SORT_H
 #define MERGE_SORT_H
 
-void Ptngc_merge_sort(void *base, size_t nmemb, size_t size,
+void Ptngc_merge_sort(void *base, const size_t nmemb, const size_t size,
 		int (*compar)(const void *v1,const void *v2,const void *private),
 		void *private);
 
diff --git a/include/compression/mtf.h b/include/compression/mtf.h
index bc4b2c8..3dc9ace 100644
--- a/include/compression/mtf.h
+++ b/include/compression/mtf.h
@@ -12,24 +12,24 @@
 #ifndef MTF_H
 #define MTF_H
 
-void Ptngc_comp_conv_to_mtf(unsigned int *vals, int nvals,
-		      unsigned int *dict, int ndict,
+void Ptngc_comp_conv_to_mtf(unsigned int *vals, const int nvals,
+		      unsigned int *dict, const int ndict,
 		      unsigned int *valsmtf);
 
-void Ptngc_comp_conv_from_mtf(unsigned int *valsmtf, int nvals,
-			unsigned int *dict, int ndict,
+void Ptngc_comp_conv_from_mtf(unsigned int *valsmtf, const int nvals,
+			unsigned int *dict, const int ndict,
 			unsigned int *vals);
 
-void Ptngc_comp_conv_to_mtf_partial(unsigned int *vals, int nvals,
+void Ptngc_comp_conv_to_mtf_partial(unsigned int *vals, const int nvals,
 			      unsigned int *valsmtf);
 
-void Ptngc_comp_conv_from_mtf_partial(unsigned int *valsmtf, int nvals,
+void Ptngc_comp_conv_from_mtf_partial(unsigned int *valsmtf, const int nvals,
 				unsigned int *vals);
 
-void Ptngc_comp_conv_to_mtf_partial3(unsigned int *vals, int nvals,
+void Ptngc_comp_conv_to_mtf_partial3(unsigned int *vals, const int nvals,
 			       unsigned char *valsmtf);
 
-void Ptngc_comp_conv_from_mtf_partial3(unsigned char *valsmtf, int nvals,
+void Ptngc_comp_conv_from_mtf_partial3(unsigned char *valsmtf, const int nvals,
 				 unsigned int *vals);
 
 #endif
diff --git a/include/compression/rle.h b/include/compression/rle.h
index c6d4706..3665dd0 100644
--- a/include/compression/rle.h
+++ b/include/compression/rle.h
@@ -12,11 +12,11 @@
 #ifndef RLE_H
 #define RLE_H
 
-void Ptngc_comp_conv_to_rle(unsigned int *vals, int nvals,
-		      unsigned int *rle, int *nrle,
-		      int min_rle);
+void Ptngc_comp_conv_to_rle(unsigned int *vals, const int nvals,
+		                    unsigned int *rle, int *nrle,
+		                    const int min_rle);
 
 void Ptngc_comp_conv_from_rle(unsigned int *rle,
-			unsigned int *vals, int nvals);
+			                  unsigned int *vals, const int nvals);
 
 #endif
diff --git a/include/compression/tng_compress.h b/include/compression/tng_compress.h
index c8b8db1..0082ba3 100644
--- a/include/compression/tng_compress.h
+++ b/include/compression/tng_compress.h
@@ -50,18 +50,18 @@
    If too large values are input (compared to the precision), NULL is returned.
 */
 
-char DECLSPECDLLEXPORT *tng_compress_pos(double *pos, int natoms, int nframes,
-					 double desired_precision,
-					 int speed, int *algo,
+char DECLSPECDLLEXPORT *tng_compress_pos(double *pos, const int natoms, const int nframes,
+					 const double desired_precision,
+					 const int speed, int *algo,
 					 int *nitems);
 
-char DECLSPECDLLEXPORT *tng_compress_pos_float(float *pos, int natoms, int nframes,
-					       float desired_precision,
-					       int speed, int *algo,
+char DECLSPECDLLEXPORT *tng_compress_pos_float(float *pos, const int natoms, const int nframes,
+					       const float desired_precision,
+					       const int speed, int *algo,
 					       int *nitems);
 
-char DECLSPECDLLEXPORT *tng_compress_pos_int(int *pos, int natoms, int nframes,
-					     unsigned long prec_hi, unsigned long prec_lo,
+char DECLSPECDLLEXPORT *tng_compress_pos_int(int *pos, const int natoms, const int nframes,
+					     const unsigned long prec_hi, const unsigned long prec_lo,
 					     int speed,int *algo,
 					     int *nitems);
 
@@ -90,21 +90,21 @@ char DECLSPECDLLEXPORT *tng_compress_pos_int(int *pos, int natoms, int nframes,
    by calling tng_compress_nalgo
 */
 
-char DECLSPECDLLEXPORT *tng_compress_pos_find_algo(double *pos, int natoms, int nframes,
-						   double desired_precision,
-						   int speed,
+char DECLSPECDLLEXPORT *tng_compress_pos_find_algo(double *pos, const int natoms, const int nframes,
+						   const double desired_precision,
+						   const int speed,
 						   int *algo,
 						   int *nitems);
 
-char DECLSPECDLLEXPORT *tng_compress_pos_float_find_algo(float *pos, int natoms, int nframes,
-							 float desired_precision,
-							 int speed,
+char DECLSPECDLLEXPORT *tng_compress_pos_float_find_algo(float *pos, const int natoms, const int nframes,
+							 const float desired_precision,
+							 const int speed,
 							 int *algo,
 							 int *nitems);
 
-char DECLSPECDLLEXPORT *tng_compress_pos_int_find_algo(int *pos, int natoms, int nframes,
-						       unsigned long prec_hi, unsigned long prec_lo,
-						       int speed,int *algo,
+char DECLSPECDLLEXPORT *tng_compress_pos_int_find_algo(int *pos, const int natoms, const int nframes,
+						       const unsigned long prec_hi, const unsigned long prec_lo,
+						       const int speed, int *algo,
 						       int *nitems);
 
 /* This returns the number of integers required for the storage of the algorithm
@@ -116,36 +116,36 @@ int DECLSPECDLLEXPORT tng_compress_nalgo(void);
    selection for velocities is different, so the position and
    velocities routines should not be mixed. */
 
-char DECLSPECDLLEXPORT *tng_compress_vel(double *vel, int natoms, int nframes,
-					 double desired_precision,
-					 int speed, int *algo,
+char DECLSPECDLLEXPORT *tng_compress_vel(double *vel, const int natoms, const int nframes,
+					 const double desired_precision,
+					 const int speed, int *algo,
 					 int *nitems);
 
-char DECLSPECDLLEXPORT *tng_compress_vel_float(float *vel, int natoms, int nframes,
-					       float desired_precision,
-					       int speed, int *algo,
+char DECLSPECDLLEXPORT *tng_compress_vel_float(float *vel, const int natoms, const int nframes,
+					       const float desired_precision,
+					       const int speed, int *algo,
 					       int *nitems);
 
-char DECLSPECDLLEXPORT *tng_compress_vel_int(int *vel, int natoms, int nframes,
-					     unsigned long prec_hi, unsigned long prec_lo,
+char DECLSPECDLLEXPORT *tng_compress_vel_int(int *vel, const int natoms, const int nframes,
+					     const unsigned long prec_hi, const unsigned long prec_lo,
 					     int speed, int *algo,
 					     int *nitems);
 
-char DECLSPECDLLEXPORT *tng_compress_vel_find_algo(double *vel, int natoms, int nframes,
-						   double desired_precision,
-						   int speed,
+char DECLSPECDLLEXPORT *tng_compress_vel_find_algo(double *vel, const int natoms, const int nframes,
+						   const double desired_precision,
+						   const int speed,
 						   int *algo,
 						   int *nitems);
 
-char DECLSPECDLLEXPORT *tng_compress_vel_float_find_algo(float *vel, int natoms, int nframes,
-							 float desired_precision,
-							 int speed,
+char DECLSPECDLLEXPORT *tng_compress_vel_float_find_algo(float *vel, const int natoms, const int nframes,
+							 const float desired_precision,
+							 const int speed,
 							 int *algo,
 							 int *nitems);
 
-char DECLSPECDLLEXPORT *tng_compress_vel_int_find_algo(int *vel, int natoms, int nframes,
-						       unsigned long prec_hi, unsigned long prec_lo,
-						       int speed,
+char DECLSPECDLLEXPORT *tng_compress_vel_int_find_algo(int *vel, const int natoms, const int nframes,
+						       const unsigned long prec_hi, const unsigned long prec_lo,
+						       const int speed,
 						       int *algo,
 						       int *nitems);
 
@@ -170,12 +170,12 @@ int DECLSPECDLLEXPORT tng_compress_uncompress_int(char *data,int *posvel, unsign
 
 /* This converts a block of integers, as obtained from tng_compress_uncompress_int, to floating point values
    either double precision or single precision. */
-void DECLSPECDLLEXPORT tng_compress_int_to_double(int *posvel_int,unsigned long prec_hi, unsigned long prec_lo,
-						  int natoms,int nframes,
+void DECLSPECDLLEXPORT tng_compress_int_to_double(int *posvel_int, const unsigned long prec_hi, const unsigned long prec_lo,
+						  const int natoms, const int nframes,
 						  double *posvel_double);
 
-void DECLSPECDLLEXPORT tng_compress_int_to_float(int *posvel_int,unsigned long prec_hi, unsigned long prec_lo,
-						 int natoms,int nframes,
+void DECLSPECDLLEXPORT tng_compress_int_to_float(int *posvel_int, const unsigned long prec_hi, const unsigned long prec_lo,
+						 const int natoms, const int nframes,
 						 float *posvel_float);
 
 
diff --git a/include/compression/vals16.h b/include/compression/vals16.h
index 4585755..ba1b8fb 100644
--- a/include/compression/vals16.h
+++ b/include/compression/vals16.h
@@ -12,10 +12,10 @@
 #ifndef VALS16_H
 #define VALS16_H
 
-void Ptngc_comp_conv_to_vals16(unsigned int *vals,int nvals,
-			 unsigned int *vals16, int *nvals16);
+void Ptngc_comp_conv_to_vals16(unsigned int *vals, const int nvals,
+                               unsigned int *vals16, int *nvals16);
 
-void Ptngc_comp_conv_from_vals16(unsigned int *vals16,int nvals16,
-			   unsigned int *vals, int *nvals);
+void Ptngc_comp_conv_from_vals16(unsigned int *vals16, const int nvals16,
+                                 unsigned int *vals, int *nvals);
 
 #endif
diff --git a/include/compression/warnmalloc.h b/include/compression/warnmalloc.h
index 4444271..aa63111 100644
--- a/include/compression/warnmalloc.h
+++ b/include/compression/warnmalloc.h
@@ -14,11 +14,11 @@
 
 #include "../compression/tng_compress.h"
 
-void DECLSPECDLLEXPORT *Ptngc_warnmalloc_x(size_t size, char *file, int line);
+void DECLSPECDLLEXPORT *Ptngc_warnmalloc_x(const size_t size, char *file, const int line);
 
 #define warnmalloc(size) Ptngc_warnmalloc_x(size,__FILE__,__LINE__)
 
-void DECLSPECDLLEXPORT *Ptngc_warnrealloc_x(void *old, size_t size, char *file, int line);
+void DECLSPECDLLEXPORT *Ptngc_warnrealloc_x(void *old, const size_t size, char *file, const int line);
 
 #define warnrealloc(old,size) Ptngc_warnrealloc_x(old,size,__FILE__,__LINE__)
 
diff --git a/include/tng/tng_io.h b/include/tng/tng_io.h
index a80af58..668acbe 100644
--- a/include/tng/tng_io.h
+++ b/include/tng/tng_io.h
@@ -640,7 +640,7 @@ tng_function_status DECLSPECDLLEXPORT tng_trajectory_destroy
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_trajectory_init_from_src
-                (tng_trajectory_t src, tng_trajectory_t *dest_p);
+                (const tng_trajectory_t src, tng_trajectory_t *dest_p);
 
 /**
  * @brief Get the name of the input file.
@@ -672,7 +672,7 @@ tng_function_status DECLSPECDLLEXPORT tng_input_file_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_input_file_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *file_name);
 
 /**
@@ -705,7 +705,7 @@ tng_function_status DECLSPECDLLEXPORT tng_output_file_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_output_file_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *file_name);
 
 /**
@@ -721,7 +721,7 @@ tng_function_status DECLSPECDLLEXPORT tng_output_file_set
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_output_append_file_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *file_name);
 
 /**
@@ -752,7 +752,7 @@ tng_function_status DECLSPECDLLEXPORT tng_output_file_endianness_get
  * could not be set.
  */
 tng_function_status DECLSPECDLLEXPORT tng_output_file_endianness_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const tng_file_endianness endianness);
 
 /**
@@ -785,7 +785,7 @@ tng_function_status DECLSPECDLLEXPORT tng_first_program_name_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_first_program_name_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *new_name);
 
 /**
@@ -818,7 +818,7 @@ tng_function_status DECLSPECDLLEXPORT tng_last_program_name_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_last_program_name_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *new_name);
 
 /**
@@ -851,7 +851,7 @@ tng_function_status DECLSPECDLLEXPORT tng_first_user_name_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_first_user_name_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *new_name);
 
 /**
@@ -884,7 +884,7 @@ tng_function_status DECLSPECDLLEXPORT tng_last_user_name_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_last_user_name_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *new_name);
 
 /**
@@ -917,7 +917,7 @@ tng_function_status DECLSPECDLLEXPORT tng_first_computer_name_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_first_computer_name_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *new_name);
 
 /**
@@ -950,7 +950,7 @@ tng_function_status DECLSPECDLLEXPORT tng_last_computer_name_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_last_computer_name_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *new_name);
 
 /**
@@ -983,7 +983,7 @@ tng_function_status DECLSPECDLLEXPORT tng_first_signature_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_first_signature_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *signature);
 
 /**
@@ -1016,7 +1016,7 @@ tng_function_status DECLSPECDLLEXPORT tng_last_signature_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_last_signature_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *signature);
 
 /**
@@ -1049,7 +1049,7 @@ tng_function_status DECLSPECDLLEXPORT tng_forcefield_name_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_forcefield_name_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *new_name);
 
 /**
@@ -1075,7 +1075,7 @@ tng_function_status DECLSPECDLLEXPORT tng_medium_stride_length_get
  * has occurred.
  */
 tng_function_status DECLSPECDLLEXPORT tng_medium_stride_length_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t len);
 
 /**
@@ -1101,7 +1101,7 @@ tng_function_status DECLSPECDLLEXPORT tng_long_stride_length_get
  * has occurred.
  */
 tng_function_status DECLSPECDLLEXPORT tng_long_stride_length_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t len);
 
 /**
@@ -1128,7 +1128,7 @@ tng_function_status DECLSPECDLLEXPORT tng_time_per_frame_get
  * has occurred.
  */
 tng_function_status DECLSPECDLLEXPORT tng_time_per_frame_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const double time);
 
 /**
@@ -1187,7 +1187,7 @@ tng_function_status DECLSPECDLLEXPORT tng_compression_precision_get
  * @return TNG_SUCCESS (0) if successful.
  */
 tng_function_status DECLSPECDLLEXPORT tng_compression_precision_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const double precision);
 
 /**
@@ -1202,7 +1202,7 @@ tng_function_status DECLSPECDLLEXPORT tng_compression_precision_set
  * @return TNG_SUCCESS (0) if successful.
  */
 tng_function_status DECLSPECDLLEXPORT tng_implicit_num_particles_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t n);
 
 /**
@@ -1378,7 +1378,7 @@ tng_function_status DECLSPECDLLEXPORT tng_current_frame_set_get
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_frame_set_nr_find
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t nr);
 
 /**
@@ -1394,7 +1394,7 @@ tng_function_status DECLSPECDLLEXPORT tng_frame_set_nr_find
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_frame_set_of_frame_find
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame);
 
 /**
@@ -1480,7 +1480,7 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_free(const tng_trajectory_t t
  */
 tng_function_status DECLSPECDLLEXPORT tng_molecule_init
                 (const tng_trajectory_t tng_data,
-                 tng_molecule_t molecule);
+                 const tng_molecule_t molecule);
 
 /**
  * @brief Clean up a molecule container.
@@ -1493,7 +1493,7 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_init
  */
 tng_function_status DECLSPECDLLEXPORT tng_molecule_destroy
                 (const tng_trajectory_t tng_data,
-                 tng_molecule_t molecule);
+                 const tng_molecule_t molecule);
 
 /**
  * @brief Add a molecule to the trajectory.
@@ -1508,7 +1508,7 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_destroy
  * not be set properly or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_molecule_add
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *name,
                  tng_molecule_t *molecule);
 
@@ -1526,7 +1526,7 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_add
  * not be set properly or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_molecule_w_id_add
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *name,
                  const int64_t id,
                  tng_molecule_t *molecule);
@@ -1542,7 +1542,7 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_w_id_add
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_molecule_existing_add
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  tng_molecule_t *molecule);
 
 /**
@@ -1578,8 +1578,8 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_name_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_molecule_name_set
-                (tng_trajectory_t tng_data,
-                 tng_molecule_t molecule,
+                (const tng_trajectory_t tng_data,
+                 const tng_molecule_t molecule,
                  const char *new_name);
 
 /**
@@ -1610,8 +1610,8 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_cnt_get
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_molecule_cnt_set
-                (tng_trajectory_t tng_data,
-                 tng_molecule_t molecule,
+                (const tng_trajectory_t tng_data,
+                 const tng_molecule_t molecule,
                  const int64_t cnt);
 
 /**
@@ -1632,9 +1632,9 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_cnt_set
  * be found.
  */
 tng_function_status DECLSPECDLLEXPORT tng_molecule_find
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *name,
-                 int64_t id,
+                 const int64_t id,
                  tng_molecule_t *molecule);
 
 /**
@@ -1649,8 +1649,8 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_find
  * molecule is not found.
  */
 tng_function_status DECLSPECDLLEXPORT tng_molecule_of_index_get
-                (tng_trajectory_t tng_data,
-                 int64_t index,
+                (const tng_trajectory_t tng_data,
+                 const int64_t index,
                  tng_molecule_t *molecule);
 
 /**
@@ -1667,8 +1667,8 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_of_index_get
  * @return TNG_SUCCESS(0) if the copying is successful, TNG_FAILURE if a minor
  * error has occured or TNG_CRITICAL(2) if a major error has occured.
  */
-tng_function_status DECLSPECDLLEXPORT tng_molecule_system_copy(tng_trajectory_t tng_data_src,
-                                                               tng_trajectory_t tng_data_dest);
+tng_function_status DECLSPECDLLEXPORT tng_molecule_system_copy(const tng_trajectory_t tng_data_src,
+                                                               const tng_trajectory_t tng_data_dest);
 
 /**
  * @brief Get the number of chains in a molecule.
@@ -1697,9 +1697,9 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_num_chains_get
  * chain is not found.
  */
 tng_function_status DECLSPECDLLEXPORT tng_molecule_chain_of_index_get
-                (tng_trajectory_t tng_data,
-                 tng_molecule_t molecule,
-                 int64_t index,
+                (const tng_trajectory_t tng_data,
+                 const tng_molecule_t molecule,
+                 const int64_t index,
                  tng_chain_t *chain);
 
 /**
@@ -1785,10 +1785,10 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_atom_of_index_get
  * be found.
  */
 tng_function_status DECLSPECDLLEXPORT tng_molecule_chain_find
-                (tng_trajectory_t tng_data,
-                 tng_molecule_t molecule,
+                (const tng_trajectory_t tng_data,
+                 const tng_molecule_t molecule,
                  const char *name,
-                 int64_t id,
+                 const int64_t id,
                  tng_chain_t *chain);
 
 /**
@@ -1805,8 +1805,8 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_chain_find
  * not be set properly or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_molecule_chain_add
-                (tng_trajectory_t tng_data,
-                 tng_molecule_t molecule,
+                (const tng_trajectory_t tng_data,
+                 const tng_molecule_t molecule,
                  const char *name,
                  tng_chain_t *chain);
 
@@ -1825,8 +1825,8 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_chain_add
  * not be set properly or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_molecule_chain_w_id_add
-                (tng_trajectory_t tng_data,
-                 tng_molecule_t molecule,
+                (const tng_trajectory_t tng_data,
+                 const tng_molecule_t molecule,
                  const char *name,
                  const int64_t id,
                  tng_chain_t *chain);
@@ -1845,7 +1845,7 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_chain_w_id_add
  */
 tng_function_status DECLSPECDLLEXPORT tng_molecule_bond_add
                 (const tng_trajectory_t tng_data,
-                 tng_molecule_t molecule,
+                 const tng_molecule_t molecule,
                  const int64_t from_atom_id,
                  const int64_t to_atom_id,
                  tng_bond_t *bond);
@@ -1867,10 +1867,10 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_bond_add
  * be found.
  */
 tng_function_status DECLSPECDLLEXPORT tng_molecule_atom_find
-                (tng_trajectory_t tng_data,
-                 tng_molecule_t molecule,
+                (const tng_trajectory_t tng_data,
+                 const tng_molecule_t molecule,
                  const char *name,
-                 int64_t id,
+                 const int64_t id,
                  tng_atom_t *atom);
 
 /**
@@ -1904,8 +1904,8 @@ tng_function_status DECLSPECDLLEXPORT tng_chain_name_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_chain_name_set
-                (tng_trajectory_t tng_data,
-                 tng_chain_t chain,
+                (const tng_trajectory_t tng_data,
+                 const tng_chain_t chain,
                  const char *new_name);
 
 /**
@@ -1957,10 +1957,10 @@ tng_function_status DECLSPECDLLEXPORT tng_chain_residue_of_index_get
  * be found.
  */
 tng_function_status DECLSPECDLLEXPORT tng_chain_residue_find
-                (tng_trajectory_t tng_data,
-                 tng_chain_t chain,
+                (const tng_trajectory_t tng_data,
+                 const tng_chain_t chain,
                  const char *name,
-                 int64_t id,
+                 const int64_t id,
                  tng_residue_t *residue);
 
 /**
@@ -1977,8 +1977,8 @@ tng_function_status DECLSPECDLLEXPORT tng_chain_residue_find
  * not be set properly or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_chain_residue_add
-                (tng_trajectory_t tng_data,
-                 tng_chain_t chain,
+                (const tng_trajectory_t tng_data,
+                 const tng_chain_t chain,
                  const char *name,
                  tng_residue_t *residue);
 
@@ -1997,8 +1997,8 @@ tng_function_status DECLSPECDLLEXPORT tng_chain_residue_add
  * not be set properly or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_chain_residue_w_id_add
-                (tng_trajectory_t tng_data,
-                 tng_chain_t chain,
+                (const tng_trajectory_t tng_data,
+                 const tng_chain_t chain,
                  const char *name,
                  const int64_t id,
                  tng_residue_t *residue);
@@ -2036,8 +2036,8 @@ tng_function_status DECLSPECDLLEXPORT tng_residue_name_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_residue_name_set
-                (tng_trajectory_t tng_data,
-                 tng_residue_t residue,
+                (const tng_trajectory_t tng_data,
+                 const tng_residue_t residue,
                  const char *new_name);
 
 /**
@@ -2089,8 +2089,8 @@ tng_function_status DECLSPECDLLEXPORT tng_residue_atom_of_index_get
  * not be set properly or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_residue_atom_add
-                (tng_trajectory_t tng_data,
-                 tng_residue_t residue,
+                (const tng_trajectory_t tng_data,
+                 const tng_residue_t residue,
                  const char *atom_name,
                  const char *atom_type,
                  tng_atom_t *atom);
@@ -2113,8 +2113,8 @@ tng_function_status DECLSPECDLLEXPORT tng_residue_atom_add
  * not be set properly or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_residue_atom_w_id_add
-                (tng_trajectory_t tng_data,
-                 tng_residue_t residue,
+                (const tng_trajectory_t tng_data,
+                 const tng_residue_t residue,
                  const char *atom_name,
                  const char *atom_type,
                  const int64_t id,
@@ -2165,8 +2165,8 @@ tng_function_status DECLSPECDLLEXPORT tng_atom_name_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_atom_name_set
-                (tng_trajectory_t tng_data,
-                 tng_atom_t atom,
+                (const tng_trajectory_t tng_data,
+                 const tng_atom_t atom,
                  const char *new_name);
 
 /**
@@ -2202,8 +2202,8 @@ tng_function_status DECLSPECDLLEXPORT tng_atom_type_get
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_atom_type_set
-                (tng_trajectory_t tng_data,
-                 tng_atom_t atom,
+                (const tng_trajectory_t tng_data,
+                 const tng_atom_t atom,
                  const char *new_type);
 
 /**
@@ -2224,7 +2224,7 @@ tng_function_status DECLSPECDLLEXPORT tng_molecule_name_of_particle_nr_get
                 (const tng_trajectory_t tng_data,
                  const int64_t nr,
                  char *name,
-                 int max_len);
+                 const int max_len);
 
 /**
  * @brief Get the molecule id of real particle number (number in mol system).
@@ -2290,7 +2290,7 @@ tng_function_status DECLSPECDLLEXPORT tng_chain_name_of_particle_nr_get
                 (const tng_trajectory_t tng_data,
                  const int64_t nr,
                  char *name,
-                 int max_len);
+                 const int max_len);
 
 /**
  * @brief Get the residue name of real particle number (number in mol system).
@@ -2310,7 +2310,7 @@ tng_function_status DECLSPECDLLEXPORT tng_residue_name_of_particle_nr_get
                 (const tng_trajectory_t tng_data,
                  const int64_t nr,
                  char *name,
-                 int max_len);
+                 const int max_len);
 
 /**
  * @brief Get the residue id (local to molecule) of real particle number
@@ -2364,7 +2364,7 @@ tng_function_status DECLSPECDLLEXPORT tng_atom_name_of_particle_nr_get
                 (const tng_trajectory_t tng_data,
                  const int64_t nr,
                  char *name,
-                 int max_len);
+                 const int max_len);
 
 /**
  * @brief Get the atom type of real particle number (number in mol system).
@@ -2384,7 +2384,7 @@ tng_function_status DECLSPECDLLEXPORT tng_atom_type_of_particle_nr_get
                 (const tng_trajectory_t tng_data,
                  const int64_t nr,
                  char *type,
-                 int max_len);
+                 const int max_len);
 
 /**
  * @brief Add a particle mapping table.
@@ -2408,7 +2408,7 @@ tng_function_status DECLSPECDLLEXPORT tng_atom_type_of_particle_nr_get
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_particle_mapping_add
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t num_first_particle,
                  const int64_t n_particles,
                  const int64_t *mapping_table);
@@ -2424,7 +2424,7 @@ tng_function_status DECLSPECDLLEXPORT tng_particle_mapping_add
  * @return TNG_SUCCESS (0) if successful.
  */
 tng_function_status DECLSPECDLLEXPORT tng_frame_set_particle_mapping_free
-                (tng_trajectory_t tng_data);
+                (const tng_trajectory_t tng_data);
 
 /**
  * @brief Read the header blocks from the input_file of tng_data.
@@ -2443,7 +2443,7 @@ tng_function_status DECLSPECDLLEXPORT tng_frame_set_particle_mapping_free
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_file_headers_read
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char hash_mode);
 
 /**
@@ -2462,7 +2462,7 @@ tng_function_status DECLSPECDLLEXPORT tng_file_headers_read
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_file_headers_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char hash_mode);
 
 /**
@@ -2486,8 +2486,8 @@ tng_function_status DECLSPECDLLEXPORT tng_file_headers_write
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_block_read_next
-                (tng_trajectory_t tng_data,
-                 tng_gen_block_t block_data,
+                (const tng_trajectory_t tng_data,
+                 const tng_gen_block_t block_data,
                  const char hash_mode);
 
 /**
@@ -2503,7 +2503,7 @@ tng_function_status DECLSPECDLLEXPORT tng_block_read_next
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_frame_set_read
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char hash_mode);
 
 /**
@@ -2523,7 +2523,7 @@ tng_function_status DECLSPECDLLEXPORT tng_frame_set_read
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_frame_set_read_current_only_data_from_block_id
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char hash_mode,
                  const int64_t block_id);
 
@@ -2543,7 +2543,7 @@ tng_function_status DECLSPECDLLEXPORT tng_frame_set_read_current_only_data_from_
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_frame_set_read_next
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char hash_mode);
 
 /**
@@ -2563,7 +2563,7 @@ tng_function_status DECLSPECDLLEXPORT tng_frame_set_read_next
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_frame_set_read_next_only_data_from_block_id
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char hash_mode,
                  const int64_t block_id);
 
@@ -2582,7 +2582,7 @@ tng_function_status DECLSPECDLLEXPORT tng_frame_set_read_next_only_data_from_blo
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_frame_set_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char hash_mode);
 
 /**
@@ -2603,7 +2603,7 @@ tng_function_status DECLSPECDLLEXPORT tng_frame_set_write
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_frame_set_premature_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char hash_mode);
 
 /**
@@ -2622,7 +2622,7 @@ tng_function_status DECLSPECDLLEXPORT tng_frame_set_premature_write
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_frame_set_new
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t first_frame,
                  const int64_t n_frames);
 
@@ -2644,7 +2644,7 @@ tng_function_status DECLSPECDLLEXPORT tng_frame_set_new
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_frame_set_with_time_new
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t first_frame,
                  const int64_t n_frames,
                  const double first_frame_time);
@@ -2661,7 +2661,7 @@ tng_function_status DECLSPECDLLEXPORT tng_frame_set_with_time_new
  * @return TNG_SUCCESS (0) if successful.
  */
 tng_function_status DECLSPECDLLEXPORT tng_frame_set_first_frame_time_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const double first_frame_time);
 
 /**
@@ -2710,7 +2710,7 @@ tng_function_status DECLSPECDLLEXPORT tng_first_frame_nr_of_next_frame_set_get
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_data_block_add
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t id,
                  const char *block_name,
                  const char datatype,
@@ -2755,7 +2755,7 @@ tng_function_status DECLSPECDLLEXPORT tng_data_block_add
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_particle_data_block_add
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t id,
                  const char *block_name,
                  const char datatype,
@@ -2783,10 +2783,10 @@ tng_function_status DECLSPECDLLEXPORT tng_particle_data_block_add
  * TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_data_block_name_get
-                (tng_trajectory_t tng_data,
-                 int64_t block_id,
+                (const tng_trajectory_t tng_data,
+                 const int64_t block_id,
                  char *name,
-                 int max_len);
+                 const int max_len);
 
 /** @brief Get the dependency of a data block of a specific ID.
  * @param tng_data is the trajectory data container.
@@ -2805,7 +2805,7 @@ tng_function_status DECLSPECDLLEXPORT tng_data_block_name_get
  */
 tng_function_status DECLSPECDLLEXPORT tng_data_block_dependency_get
                 (const tng_trajectory_t tng_data,
-                 int64_t block_id,
+                 const int64_t block_id,
                  int *block_dependency);
 
 /** @brief Get the number of values per frame of a data block of a specific ID.
@@ -2822,7 +2822,7 @@ tng_function_status DECLSPECDLLEXPORT tng_data_block_dependency_get
  */
 tng_function_status DECLSPECDLLEXPORT tng_data_block_num_values_per_frame_get
                 (const tng_trajectory_t tng_data,
-                 int64_t block_id,
+                 const int64_t block_id,
                  int64_t *n_values_per_frame);
 
 /**
@@ -2846,7 +2846,7 @@ tng_function_status DECLSPECDLLEXPORT tng_data_block_num_values_per_frame_get
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_frame_data_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const int64_t block_id,
                  const void *values,
@@ -2880,7 +2880,7 @@ tng_function_status DECLSPECDLLEXPORT tng_frame_data_write
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_frame_particle_data_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const int64_t block_id,
                  const int64_t val_first_particle,
@@ -2957,7 +2957,7 @@ tng_function_status DECLSPECDLLEXPORT tng_particle_data_values_free
  * @return TNG_SUCCESS (0) if successful, TNG_FAILURE (1) if a minor error
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
-tng_function_status DECLSPECDLLEXPORT tng_data_get(tng_trajectory_t tng_data,
+tng_function_status DECLSPECDLLEXPORT tng_data_get(const tng_trajectory_t tng_data,
                                                    const int64_t block_id,
                                                    union data_values ***values,
                                                    int64_t *n_frames,
@@ -2995,7 +2995,7 @@ tng_function_status DECLSPECDLLEXPORT tng_data_get(tng_trajectory_t tng_data,
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_data_vector_get
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t block_id,
                  void **values,
                  int64_t *n_frames,
@@ -3036,7 +3036,7 @@ tng_function_status DECLSPECDLLEXPORT tng_data_vector_get
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_data_interval_get
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t block_id,
                  const int64_t start_frame_nr,
                  const int64_t end_frame_nr,
@@ -3081,7 +3081,7 @@ tng_function_status DECLSPECDLLEXPORT tng_data_interval_get
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_data_vector_interval_get
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t block_id,
                  const int64_t start_frame_nr,
                  const int64_t end_frame_nr,
@@ -3128,7 +3128,7 @@ tng_function_status DECLSPECDLLEXPORT tng_data_vector_interval_get
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_particle_data_get
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t block_id,
                  union data_values ****values,
                  int64_t *n_frames,
@@ -3173,7 +3173,7 @@ tng_function_status DECLSPECDLLEXPORT tng_particle_data_get
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_particle_data_vector_get
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t block_id,
                  void **values,
                  int64_t *n_frames,
@@ -3224,7 +3224,7 @@ tng_function_status DECLSPECDLLEXPORT tng_particle_data_vector_get
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_particle_data_interval_get
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t block_id,
                  const int64_t start_frame_nr,
                  const int64_t end_frame_nr,
@@ -3278,7 +3278,7 @@ tng_function_status DECLSPECDLLEXPORT tng_particle_data_interval_get
  * has occurred or TNG_CRITICAL (2) if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_particle_data_vector_interval_get
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t block_id,
                  const int64_t start_frame_nr,
                  const int64_t end_frame_nr,
@@ -3374,7 +3374,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_trajectory_close
  * minor error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_time_of_frame_get
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  double *time);
 
@@ -3392,7 +3392,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_time_of_frame_get
  * @return TNG_SUCCESS (0) if successful.
  */
 /*tng_function_status DECLSPECDLLEXPORT tng_util_trajectory_molecules_get
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  int64_t *n_mols,
                  int64_t **molecule_cnt_list,
                  tng_molecule_t *mols);
@@ -3410,14 +3410,14 @@ tng_function_status DECLSPECDLLEXPORT tng_util_time_of_frame_get
  * has occured or TNG_CRITICAL (2) if a major error has occured.
  */
 /*tng_function_status DECLSPECDLLEXPORT tng_util_trajectory_molecule_add
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const char *name,
                  const int64_t cnt,
                  tng_molecule_t *mol);
 */
 /*
 // tng_function_status DECLSPECDLLEXPORT tng_util_molecule_particles_get
-//                 (tng_trajectory_t tng_data,
+//                 (const tng_trajectory_t tng_data,
 //                  const tng_molecule_t mol,
 //                  int64_t *n_particles,
 //                  char ***names,
@@ -3428,7 +3428,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_time_of_frame_get
 //                  int64_t **chain_ids);
 //
 // tng_function_status DECLSPECDLLEXPORT tng_util_molecule_particles_set
-//                 (tng_trajectory_t tng_data,
+//                 (const tng_trajectory_t tng_data,
 //                  tng_molecule_t mol,
 //                  const int64_t n_particles,
 //                  const char **names,
@@ -3459,7 +3459,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_time_of_frame_get
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_pos_read
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  float **positions,
                  int64_t *stride_length);
 
@@ -3484,7 +3484,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_pos_read
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_vel_read
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  float **velocities,
                  int64_t *stride_length);
 
@@ -3509,7 +3509,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_vel_read
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_force_read
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  float **forces,
                  int64_t *stride_length);
 
@@ -3537,7 +3537,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_force_read
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_read
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  float **box_shape,
                  int64_t *stride_length);
 
@@ -3572,7 +3572,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_read
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_particle_data_next_frame_read
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t block_id,
                  void **values,
                  char *data_type,
@@ -3608,7 +3608,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_particle_data_next_frame_read
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_non_particle_data_next_frame_read
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t block_id,
                  void **values,
                  char *data_type,
@@ -3640,7 +3640,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_non_particle_data_next_frame_read
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_pos_read_range
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t first_frame,
                  const int64_t last_frame,
                  float **positions,
@@ -3671,7 +3671,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_pos_read_range
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_vel_read_range
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t first_frame,
                  const int64_t last_frame,
                  float **velocities,
@@ -3702,7 +3702,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_vel_read_range
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_force_read_range
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t first_frame,
                  const int64_t last_frame,
                  float **forces,
@@ -3739,7 +3739,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_force_read_range
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_read_range
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t first_frame,
                  const int64_t last_frame,
                  float **box_shape,
@@ -3774,7 +3774,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_read_range
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_generic_write_interval_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t i,
                  const int64_t n_values_per_frame,
                  const int64_t block_id,
@@ -3812,7 +3812,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_generic_write_interval_set
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_generic_write_interval_double_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t i,
                  const int64_t n_values_per_frame,
                  const int64_t block_id,
@@ -3849,7 +3849,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_generic_write_interval_double_set
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_generic_write_frequency_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t i,
                  const int64_t n_values_per_frame,
                  const int64_t block_id,
@@ -3873,7 +3873,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_generic_write_frequency_set
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_pos_write_interval_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t i);
 
 /**
@@ -3892,7 +3892,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_pos_write_interval_set
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_pos_write_interval_double_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t i);
 
 /**
@@ -3913,7 +3913,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_pos_write_interval_double_set
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_pos_write_frequency_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t i);
 
 /**
@@ -3932,7 +3932,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_pos_write_frequency_set
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_vel_write_interval_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t i);
 
 /**
@@ -3951,7 +3951,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_vel_write_interval_set
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_vel_write_interval_double_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t i);
 
 /**
@@ -3969,7 +3969,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_vel_write_interval_double_set
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_vel_write_frequency_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t i);
 
 /**
@@ -3988,7 +3988,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_vel_write_frequency_set
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_force_write_interval_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t i);
 
 /**
@@ -4007,7 +4007,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_force_write_interval_set
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_force_write_interval_double_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t i);
 
 /**
@@ -4025,7 +4025,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_force_write_interval_double_set
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_force_write_frequency_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t i);
 
 /**
@@ -4044,7 +4044,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_force_write_frequency_set
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_write_interval_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t i);
 
 /**
@@ -4063,7 +4063,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_write_interval_set
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_write_interval_double_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t i);
 
 /**
@@ -4081,7 +4081,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_write_interval_double_s
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_write_frequency_set
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t i);
 
 /**
@@ -4120,7 +4120,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_write_frequency_set
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_generic_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const float *values,
                  const int64_t n_values_per_frame,
@@ -4166,7 +4166,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_generic_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_generic_double_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const double *values,
                  const int64_t n_values_per_frame,
@@ -4197,7 +4197,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_generic_double_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_pos_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const float *positions);
 
@@ -4224,7 +4224,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_pos_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_pos_double_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const double *positions);
 
@@ -4250,7 +4250,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_pos_double_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_vel_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const float *velocities);
 
@@ -4277,7 +4277,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_vel_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_vel_double_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const double *velocities);
 
@@ -4303,7 +4303,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_vel_double_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_force_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const float *forces);
 
@@ -4330,7 +4330,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_force_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_force_double_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const double *forces);
 
@@ -4355,7 +4355,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_force_double_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const float *box_shape);
 
@@ -4381,7 +4381,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_double_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const double *box_shape);
 
@@ -4425,7 +4425,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_double_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_generic_with_time_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const double time,
                  const float *values,
@@ -4475,7 +4475,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_generic_with_time_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_generic_with_time_double_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const double time,
                  const double *values,
@@ -4511,7 +4511,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_generic_with_time_double_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_pos_with_time_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const double time,
                  const float *positions);
@@ -4542,7 +4542,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_pos_with_time_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_pos_with_time_double_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const double time,
                  const double *positions);
@@ -4573,7 +4573,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_pos_with_time_double_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_vel_with_time_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const double time,
                  const float *velocities);
@@ -4604,7 +4604,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_vel_with_time_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_vel_with_time_double_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const double time,
                  const double *velocities);
@@ -4635,7 +4635,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_vel_with_time_double_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_force_with_time_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const double time,
                  const float *forces);
@@ -4666,7 +4666,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_force_with_time_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_force_with_time_double_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const double time,
                  const double *forces);
@@ -4696,7 +4696,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_force_with_time_double_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_with_time_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const double time,
                  const float *box_shape);
@@ -4726,7 +4726,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_with_time_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_with_time_double_write
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t frame_nr,
                  const double time,
                  const double *box_shape);
@@ -4753,7 +4753,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_box_shape_with_time_double_write
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_frame_current_compression_get
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t block_id,
                  int64_t *codec_id,
                  double  *factor);
@@ -4792,7 +4792,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_frame_current_compression_get
  * has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_trajectory_next_frame_present_data_blocks_find
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  int64_t current_frame,
                  const int64_t n_requested_data_block_ids,
                  const int64_t *requested_data_block_ids,
@@ -4858,7 +4858,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_trajectory_next_frame_present_dat
  */
 /*
 tng_function_status DECLSPECDLLEXPORT tng_util_trajectory_all_data_block_types_get
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  int64_t *n_data_blocks,
                  int64_t **data_block_ids,
                  char ***data_block_names,
@@ -4881,7 +4881,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_trajectory_all_data_block_types_g
  * if a major error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_prepare_append_after_frame
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t prev_frame);
 
 
@@ -4894,7 +4894,7 @@ tng_function_status DECLSPECDLLEXPORT tng_util_prepare_append_after_frame
  * error has occured.
  */
 tng_function_status DECLSPECDLLEXPORT tng_util_num_frames_with_data_of_block_id_get
-                (tng_trajectory_t tng_data,
+                (const tng_trajectory_t tng_data,
                  const int64_t block_id,
                  int64_t *n_frames);
 /** @} */ /* end of group2 */