From 942403f0dba0be01c5c30238ddb8f7f75d510f09 Mon Sep 17 00:00:00 2001
From: greg <greg7mdp@gmail.com>
Date: Fri, 3 Jan 2020 14:19:55 -0500
Subject: [PATCH] remove #include <functional> from phmap_fwd_decl.h

---
 parallel_hashmap/btree.h          | 14 +++++++++++++-
 parallel_hashmap/phmap_base.h     |  9 +++++++++
 parallel_hashmap/phmap_fwd_decl.h | 10 +++++-----
 3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/parallel_hashmap/btree.h b/parallel_hashmap/btree.h
index b644ec5..2886094 100644
--- a/parallel_hashmap/btree.h
+++ b/parallel_hashmap/btree.h
@@ -755,6 +755,7 @@ namespace container_internal {
         StringBtreeDefaultLess(std::less<std::string>) {}       // NOLINT
 #if PHMAP_HAVE_STD_STRING_VIEW
         StringBtreeDefaultLess(std::less<std::string_view>) {}  // NOLINT
+        StringBtreeDefaultLess(phmap::Less<std::string_view>) {}  // NOLINT
 
         phmap::weak_ordering operator()(std::string_view lhs,
                                         std::string_view rhs) const {
@@ -810,6 +811,11 @@ namespace container_internal {
         using type = StringBtreeDefaultLess;
     };
 
+    template <>
+    struct key_compare_to_adapter<phmap::Less<std::string>> {
+        using type = StringBtreeDefaultLess;
+    };
+
     template <>
     struct key_compare_to_adapter<std::greater<std::string>> {
         using type = StringBtreeDefaultGreater;
@@ -821,6 +827,11 @@ namespace container_internal {
         using type = StringBtreeDefaultLess;
     };
 
+    template <>
+    struct key_compare_to_adapter<phmap::Less<std::string_view>> {
+        using type = StringBtreeDefaultLess;
+    };
+
     template <>
     struct key_compare_to_adapter<std::greater<std::string_view>> {
         using type = StringBtreeDefaultGreater;
@@ -1071,7 +1082,8 @@ namespace container_internal {
         using use_linear_search = std::integral_constant<
             bool,
             std::is_arithmetic<key_type>::value &&
-            (std::is_same<std::less<key_type>, key_compare>::value ||
+            (std::is_same<phmap::Less<key_type>, key_compare>::value ||
+             std::is_same<std::less<key_type>, key_compare>::value ||
              std::is_same<std::greater<key_type>, key_compare>::value)>;
 
 
diff --git a/parallel_hashmap/phmap_base.h b/parallel_hashmap/phmap_base.h
index 415e88d..4cc3e00 100644
--- a/parallel_hashmap/phmap_base.h
+++ b/parallel_hashmap/phmap_base.h
@@ -80,6 +80,15 @@ struct EqualTo
     }
 };
 
+template <class T>
+struct Less
+{
+    inline bool operator()(const T& a, const T& b) const
+    {
+        return std::less<T>()(a, b);
+    }
+};
+
 namespace type_traits_internal {
 
 template <typename... Ts>
diff --git a/parallel_hashmap/phmap_fwd_decl.h b/parallel_hashmap/phmap_fwd_decl.h
index 0ae3a04..482dbab 100644
--- a/parallel_hashmap/phmap_fwd_decl.h
+++ b/parallel_hashmap/phmap_fwd_decl.h
@@ -20,7 +20,6 @@
 
 #include <memory>
 #include <utility>
-#include <functional>
 
 #if defined(PHMAP_USE_ABSL_HASH)
     namespace absl { template <class T> struct Hash; };
@@ -35,6 +34,7 @@ namespace phmap {
 #endif
 
     template <class T> struct EqualTo;
+    template <class T> struct Less;
     template <class T> using Allocator      = typename std::allocator<T>;
     template<class T1, class T2> using Pair = typename std::pair<T1, T2>;
 
@@ -128,19 +128,19 @@ namespace phmap {
         class parallel_node_hash_map;
 
     // ------------- forward declarations for btree containers ----------------------------------
-    template <typename Key, typename Compare = std::less<Key>,
+    template <typename Key, typename Compare = phmap::Less<Key>,
               typename Alloc = phmap::Allocator<Key>>
         class btree_set;
 
-    template <typename Key, typename Compare = std::less<Key>,
+    template <typename Key, typename Compare = phmap::Less<Key>,
               typename Alloc = phmap::Allocator<Key>>
         class btree_multiset;
 
-    template <typename Key, typename Value, typename Compare = std::less<Key>,
+    template <typename Key, typename Value, typename Compare = phmap::Less<Key>,
               typename Alloc = phmap::Allocator<phmap::container_internal::Pair<const Key, Value>>>
         class btree_map;
     
-    template <typename Key, typename Value, typename Compare = std::less<Key>,
+    template <typename Key, typename Value, typename Compare = phmap::Less<Key>,
               typename Alloc = phmap::Allocator<phmap::container_internal::Pair<const Key, Value>>>
         class btree_multimap;