Merge remote-tracking branch 'origin/master' into filtration

1 files changed, 2 insertions, 4 deletions

diff --git a/src/Simplex_tree/include/gudhi/Simplex_tree.h b/src/Simplex_tree/include/gudhi/Simplex_tree.h
index 43250795..889dbd00 100644
--- a/src/Simplex_tree/include/gudhi/Simplex_tree.h
+++ b/src/Simplex_tree/include/gudhi/Simplex_tree.h
@@ -486,7 +486,7 @@ class Simplex_tree {
  public:
   /** \brief Returns the key associated to a simplex.
    *
-   * The filtration must be initialized.
+   * If no key has been assigned, returns `null_key()`.
    * \pre SimplexTreeOptions::store_key
    */
   static Simplex_key key(Simplex_handle sh) {
@@ -496,7 +496,6 @@ class Simplex_tree {
   /** \brief Returns the simplex that has index idx in the filtration.
    *
    * The filtration must be initialized.
-   * \pre SimplexTreeOptions::store_key
    */
   Simplex_handle simplex(Simplex_key idx) const {
     return filtration_vect_[idx];
@@ -532,8 +531,7 @@ class Simplex_tree {
     return Dictionary_it(nullptr);
   }
 
-  /** \brief Returns a key different for all keys associated to the
-   * simplices of the simplicial complex. */
+  /** \brief Returns a fixed number not in the interval [0, `num_simplices()`).  */
   static Simplex_key null_key() {
     return -1;
   }