move number parsing to numerizer class

include/nlohmann/detail/input/lexer.hpp

@@ -13,6 +13,7 @@
 #include <nlohmann/detail/input/input_adapters.hpp>
 #include <nlohmann/detail/input/position_t.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
+#include <nlohmann/detail/input/numerizer.hpp>
 
 namespace nlohmann
 {
@@ -99,7 +100,7 @@ class lexer_base
 
 This class organizes the lexical analysis during JSON deserialization.
 */
-template<typename BasicJsonType, typename InputAdapterType>
+template<typename BasicJsonType, typename InputAdapterType, typename NumerizerType = numerizer>
 class lexer : public lexer_base<BasicJsonType>
 {
     using number_integer_t = typename BasicJsonType::number_integer_t;
@@ -900,24 +901,6 @@ class lexer : public lexer_base<BasicJsonType>
         }
     }
 
-    JSON_HEDLEY_NON_NULL(2)
-    static void strtof(float& f, const char* str, char** endptr) noexcept
-    {
-        f = std::strtof(str, endptr);
-    }
-
-    JSON_HEDLEY_NON_NULL(2)
-    static void strtof(double& f, const char* str, char** endptr) noexcept
-    {
-        f = std::strtod(str, endptr);
-    }
-
-    JSON_HEDLEY_NON_NULL(2)
-    static void strtof(long double& f, const char* str, char** endptr) noexcept
-    {
-        f = std::strtold(str, endptr);
-    }
-
     /*!
     @brief scan a number literal
 
@@ -1242,7 +1225,7 @@ scan_number_done:
         // try to parse integers first and fall back to floats
         if (number_type == token_type::value_unsigned)
         {
-            const auto x = std::strtoull(token_buffer.data(), &endptr, 10);
+            const auto x = NumerizerType::strtoull(token_buffer.data(), &endptr, 10);
 
             // we checked the number format before
             JSON_ASSERT(endptr == token_buffer.data() + token_buffer.size());
@@ -1258,7 +1241,7 @@ scan_number_done:
         }
         else if (number_type == token_type::value_integer)
         {
-            const auto x = std::strtoll(token_buffer.data(), &endptr, 10);
+            const auto x = NumerizerType::strtoll(token_buffer.data(), &endptr, 10);
 
             // we checked the number format before
             JSON_ASSERT(endptr == token_buffer.data() + token_buffer.size());
@@ -1275,7 +1258,7 @@ scan_number_done:
 
         // this code is reached if we parse a floating-point number or if an
         // integer conversion above failed
-        strtof(value_float, token_buffer.data(), &endptr);
+        NumerizerType::strtof(value_float, token_buffer.data(), &endptr);
 
         // we checked the number format before
         JSON_ASSERT(endptr == token_buffer.data() + token_buffer.size());

include/nlohmann/detail/input/numerizer.hpp

@@ -0,0 +1,44 @@
+
+#include <cstdlib> // strtof, strtod, strtold, strtoll, strtoull
+
+namespace nlohmann
+{
+namespace detail
+{
+  
+struct numerizer
+{
+    JSON_HEDLEY_NON_NULL(2)
+    static void strtof(float& f, const char* str, char** endptr) noexcept
+    {
+        f = std::strtof(str, endptr);
+    }
+
+    JSON_HEDLEY_NON_NULL(2)
+    static void strtof(double& f, const char* str, char** endptr) noexcept
+    {
+        f = std::strtod(str, endptr);
+    }
+
+    JSON_HEDLEY_NON_NULL(2)
+    static void strtof(long double& f, const char* str, char** endptr) noexcept
+    {
+        f = std::strtold(str, endptr);
+    }
+    
+    JSON_HEDLEY_NON_NULL(2)
+    static auto strtoull(const char* str, char** endptr, int base)
+    {
+        return std::strtoull(str, endptr, base);
+    }
+    
+    JSON_HEDLEY_NON_NULL(2)
+    static auto strtoll(const char* str, char** endptr, int base)
+    {
+        return std::strtoll(str, endptr, base);
+    }
+};
+
+ 
+}
+}

include/nlohmann/json_fwd.hpp

@@ -26,9 +26,14 @@ struct adl_serializer;
 
 namespace detail
 {
-template<typename BasicJsonType, typename InputAdapterType>
+template<typename BasicJsonType, typename InputAdapterType, typename NumerizerType>
 class lexer;
 
+struct numerizer;
+
+template<typename BasicJsonType, typename InputAdapterType>
+using basic_lexer = lexer<BasicJsonType, InputAdapterType, numerizer>;
+
 template<typename BasicJsonType>
 class serializer;
 }
@@ -44,7 +49,7 @@ template<template<typename U, typename V, typename... Args> class ObjectType =
          template<typename T, typename SFINAE = void> class JSONSerializer =
          adl_serializer,
          class BinaryType = std::vector<std::uint8_t>,
-         template<typename BasicJsonType, typename InputAdapterType> class LexerType = detail::lexer,
+         template<typename BasicJsonType, typename InputAdapterType> class LexerType = detail::basic_lexer,
          template<typename BasicJsonType> class SerializerType = detail::serializer>
 class basic_json;