2 files changed, 16 insertions, 13 deletions

diff --git a/src/Simplex_tree/concept/SimplexTreeOptions.h b/src/Simplex_tree/concept/SimplexTreeOptions.h
index a50a2bf1..add3ebdd 100644
--- a/src/Simplex_tree/concept/SimplexTreeOptions.h
+++ b/src/Simplex_tree/concept/SimplexTreeOptions.h
@@ -34,8 +34,8 @@ struct SimplexTreeOptions {
   /// Must be a signed integer type.
   typedef SimplexKey Simplex_key;
   /// If true, each simplex has extra storage for one `Simplex_key`. Necessary for `Persistent_cohomology`.
-  static constexpr bool store_key;
-  /// If true, each simplex has extra storage for one `Filtration_value`, and this value is propagated by operations like `Gudhi::Simplex_tree<SimplexTreeOptions>::expansion`. Without it, `Persistent_cohomology` degenerates to computing usual (non-persistent) cohomology.
-  static constexpr bool store_filtration;
+  static const bool store_key;
+  /// If true, each simplex has extra storage for one `Filtration_value`, and this value is propagated by operations like `Gudhi::Simplex_tree::expansion`. Without it, `Persistent_cohomology` degenerates to computing usual (non-persistent) cohomology.
+  static const bool store_filtration;
 };
 
diff --git a/src/Simplex_tree/include/gudhi/Simplex_tree.h b/src/Simplex_tree/include/gudhi/Simplex_tree.h
index 6e51d107..ea61fa2e 100644
--- a/src/Simplex_tree/include/gudhi/Simplex_tree.h
+++ b/src/Simplex_tree/include/gudhi/Simplex_tree.h
@@ -39,6 +39,7 @@
 #include <utility>
 #include <vector>
 #include <functional>  // for greater<>
+#include <initializer_list>
 
 namespace Gudhi {
 
@@ -531,7 +532,7 @@ class Simplex_tree {
    * The type InputVertexRange must be a range of <CODE>Vertex_handle</CODE>
    * on which we can call std::begin() function
    */
-  template<class InputVertexRange>
+  template<class InputVertexRange=std::initializer_list<Vertex_handle>>
   Simplex_handle find(const InputVertexRange & s) {
     auto first = std::begin(s);
     auto last = std::end(s);
@@ -625,7 +626,7 @@ class Simplex_tree {
    *
    * The type InputVertexRange must be a range for which .begin() and
    * .end() return input iterators, with 'value_type' Vertex_handle. */
-  template<class InputVertexRange>
+  template<class InputVertexRange=std::initializer_list<Vertex_handle>>
   std::pair<Simplex_handle, bool> insert_simplex(const InputVertexRange & simplex,
                                                  Filtration_value filtration = 0) {
     auto first = std::begin(simplex);
@@ -654,7 +655,7 @@ class Simplex_tree {
    * output pair to the Simplex_handle of the simplex. Otherwise, we set the Simplex_handle part to
    * null_simplex.
    */
-  template<class InputVertexRange>
+  template<class InputVertexRange=std::initializer_list<Vertex_handle>>
   std::pair<Simplex_handle, bool> insert_simplex_and_subfaces(const InputVertexRange& Nsimplex,
                                    Filtration_value filtration = 0) {
     auto first = std::begin(Nsimplex);
@@ -771,12 +772,6 @@ class Simplex_tree {
    * assigned a Simplex_key corresponding to its order in the filtration (from 0 to m-1 for a
    * simplicial complex with m simplices).
    *
-   * The use of a depth-first traversal of the simplex tree, provided by
-   * complex_simplex_range(), combined with
-   * a stable sort is meant to optimize the order of simplices with same
-   * filtration value. The heuristic consists in inserting the cofaces of a
-   * simplex as soon as possible.
-   *
    * Will be automatically called when calling filtration_simplex_range()
    * if the filtration has never been initialized yet. */
   void initialize_filtration() {
@@ -785,7 +780,15 @@ class Simplex_tree {
     for (Simplex_handle sh : complex_simplex_range())
       filtration_vect_.push_back(sh);
 
-    // the stable sort ensures the ordering heuristic
+    /* We use stable_sort here because with libstdc++ it is faster than sort.
+     * is_before_in_filtration is now a total order, but we used to call
+     * stable_sort for the following heuristic:
+     * The use of a depth-first traversal of the simplex tree, provided by
+     * complex_simplex_range(), combined with a stable sort is meant to
+     * optimize the order of simplices with same filtration value. The
+     * heuristic consists in inserting the cofaces of a simplex as soon as
+     * possible.
+     */
     std::stable_sort(filtration_vect_.begin(), filtration_vect_.end(),
                      is_before_in_filtration(this));
   }