Added tng_num_molecule_types_get()

2 files changed, 25 insertions, 0 deletions

diff --git a/include/tng_io.h b/include/tng_io.h
index 6ce98d0..50eb3dd 100644
--- a/include/tng_io.h
+++ b/include/tng_io.h
@@ -1145,6 +1145,19 @@ tng_function_status DECLSPECDLLEXPORT tng_num_particles_get
                  int64_t *n);
 
 /**
+ * @brief Get the number of molecule types (length of tng_data->molecules).
+ * @param tng_data is the trajectory from which to get the number of molecules.
+ * @param n is pointing to a value set to the number of molecule types.
+ * @pre \code tng_data != 0 \endcode The trajectory container (tng_data)
+ * must be initialised before using it.
+ * @pre \code n != 0 \endcode The pointer to n must not be a NULL pointer.
+ * @return TNG_SUCCESS (0) if successful.
+ */
+tng_function_status DECLSPECDLLEXPORT tng_num_molecules_types_get
+                (const tng_trajectory_t tng_data,
+                 int64_t *n);
+
+/**
  * @brief Get the current total number of molecules.
  * @param tng_data is the trajectory from which to get the number of molecules.
  * @param n is pointing to a value set to the number of molecules.
diff --git a/src/lib/tng_io.c b/src/lib/tng_io.c
index 364df13..850c4ef 100644
--- a/src/lib/tng_io.c
+++ b/src/lib/tng_io.c
@@ -9849,6 +9849,18 @@ tng_function_status DECLSPECDLLEXPORT tng_num_particles_get
     return(TNG_SUCCESS);
 }
 
+tng_function_status DECLSPECDLLEXPORT tng_num_molecule_types_get
+                    (const tng_trajectory_t tng_data,
+                     int64_t *n)
+{
+    TNG_ASSERT(tng_data, "TNG library: Trajectory container not properly setup.");
+    TNG_ASSERT(n, "TNG library: n must not be a NULL pointer");
+
+    *n = tng_data->n_molecules;
+
+    return(TNG_SUCCESS);
+}
+
 tng_function_status DECLSPECDLLEXPORT tng_num_molecules_get
                     (const tng_trajectory_t tng_data,
                      int64_t *n)