* Implemented C++20 contains() for associative containers as specified in P0458R2.

* Fixed serious bug in heterogeneous lookup functions (is_transparent was broken).

test/flat_map_test.cpp

@@ -454,6 +454,8 @@ struct get_real_stored_allocator<flat_multimap<Key, T, Compare, Allocator> >
 
 bool test_heterogeneous_lookups()
 {
+   BOOST_STATIC_ASSERT((dtl::is_transparent<less_transparent>::value));
+   BOOST_STATIC_ASSERT(!(dtl::is_transparent<std::less<int> >::value));
    typedef flat_map<int, char, less_transparent> map_t;
    typedef flat_multimap<int, char, less_transparent> mmap_t;
    typedef map_t::value_type value_type;
@@ -498,6 +500,16 @@ bool test_heterogeneous_lookups()
    if(cmmap1.count(find_me) != 2)
       return false;
 
+   //contains
+   if(!map1.contains(find_me))
+      return false;
+   if(!cmap1.contains(find_me))
+      return false;
+   if(!mmap1.contains(find_me))
+      return false;
+   if(!cmmap1.contains(find_me))
+      return false;
+
    //lower_bound
    if(map1.lower_bound(find_me)->second != 'd')
       return false;
@@ -709,4 +721,3 @@ int main()
 }
 
 #include <boost/container/detail/config_end.hpp>
-

test/flat_set_test.cpp

@@ -495,6 +495,16 @@ bool test_heterogeneous_lookups()
    if(cmset1.count(find_me) != 2)
       return false;
 
+   //contains
+   if(!set1.contains(find_me))
+      return false;
+   if(!cset1.contains(find_me))
+      return false;
+   if(!mset1.contains(find_me))
+      return false;
+   if(!cmset1.contains(find_me))
+      return false;
+
    //lower_bound
    if(*set1.lower_bound(find_me) != 2)
       return false;

test/map_test.cpp

@@ -366,6 +366,16 @@ bool test_heterogeneous_lookups()
    if(cmmap1.count(find_me) != 2)
       return false;
 
+   //contains
+   if(!map1.contains(find_me))
+      return false;
+   if(!cmap1.contains(find_me))
+      return false;
+   if(!mmap1.contains(find_me))
+      return false;
+   if(!cmmap1.contains(find_me))
+      return false;
+
    //lower_bound
    if(map1.lower_bound(find_me)->second != 'd')
       return false;

test/map_test.hpp

@@ -628,16 +628,24 @@ int map_test()
          }
       }
 
-      //Compare count with std containers
+      //Compare count/contains with std containers
       for(int i = 0; i < MaxElem; ++i){
          IntType k(i);
          if(boostmap.count(k) != stdmap.count(i)){
             return -1;
          }
 
+         if(boostmap.contains(k) != (stdmap.find(i) != stdmap.end())){
+            return -1;
+         }
+
          if(boostmultimap.count(k) != stdmultimap.count(i)){
             return -1;
          }
+
+         if(boostmultimap.contains(k) != (stdmultimap.find(i) != stdmultimap.end())){
+            return -1;
+         }
       }
 
       //Now do count exercise

test/set_test.cpp

@@ -363,6 +363,16 @@ bool test_heterogeneous_lookups()
    if(cmset1.count(find_me) != 2)
       return false;
 
+   //contains
+   if(!set1.contains(find_me))
+      return false;
+   if(!cset1.contains(find_me))
+      return false;
+   if(!mset1.contains(find_me))
+      return false;
+   if(!cmset1.contains(find_me))
+      return false;
+
    //lower_bound
    if(*set1.lower_bound(find_me) != 2)
       return false;

test/set_test.hpp

@@ -580,11 +580,20 @@ int set_test ()
 
    //Compare count with std containers
    for(int i = 0; i < MaxElem; ++i){
-      IntType count_me(i);
-      if(boostset.count(count_me) != stdset.count(i)){
+      IntType k(i);
+      if(boostset.count(k) != stdset.count(i)){
          return -1;
       }
-      if(boostmultiset.count(count_me) != stdmultiset.count(i)){
+
+      if(boostset.contains(k) != (stdset.find(i) != stdset.end())){
+         return -1;
+      }
+
+      if(boostmultiset.count(k) != stdmultiset.count(i)){
+         return -1;
+      }
+
+      if(boostmultiset.contains(k) != (stdmultiset.find(i) != stdmultiset.end())){
          return -1;
       }
    }