Applies PR nlohmann/json#212 to support gcc 4.8.

Author: guillaumeblanc

extern/json/README.ozz

@@ -8,3 +8,4 @@ Local Modifications:
 - Extracted include and source files from json package.
 - Striped from unsued files.
 - Creates a specific CMakeLists.txt
+- Applies PR https://github.com/nlohmann/json/pull/212 to support gcc 4.8.

extern/json/src/json.hpp

@@ -63,7 +63,7 @@ SOFTWARE.
         #error "unsupported Clang version - see https://github.com/nlohmann/json#supported-compilers"
     #endif
 #elif defined(__GNUC__)
-    #if (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) < 40900
+    #if (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) < 40800
         #error "unsupported GCC version - see https://github.com/nlohmann/json#supported-compilers"
     #endif
 #endif
@@ -5603,7 +5603,10 @@ class basic_json
 
             // insert to array and return iterator
             iterator result(this);
-            result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, cnt, val);
+            auto insert_pos = std::distance(m_value.array->begin(), pos.m_it.array_iterator);
+            m_value.array->insert(pos.m_it.array_iterator, cnt, val);
+            result.m_it.array_iterator = m_value.array->begin() + insert_pos;
+
             return result;
         }
 
@@ -5667,10 +5670,12 @@ class basic_json
 
         // insert to array and return iterator
         iterator result(this);
-        result.m_it.array_iterator = m_value.array->insert(
-                                         pos.m_it.array_iterator,
-                                         first.m_it.array_iterator,
-                                         last.m_it.array_iterator);
+        auto insert_pos = std::distance(m_value.array->begin(), pos.m_it.array_iterator);
+        m_value.array->insert(pos.m_it.array_iterator,
+                              first.m_it.array_iterator,
+                              last.m_it.array_iterator);
+        result.m_it.array_iterator = m_value.array->begin() + insert_pos;
+
         return result;
     }
 
@@ -5714,7 +5719,10 @@ class basic_json
 
         // insert to array and return iterator
         iterator result(this);
-        result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, ilist);
+        auto insert_pos = std::distance(m_value.array->begin(), pos.m_it.array_iterator);
+        m_value.array->insert(pos.m_it.array_iterator, ilist);
+        result.m_it.array_iterator = m_value.array->begin() + insert_pos;
+
         return result;
     }