CXX-3325 condition fix on GCC version (#1456)

Restore support for GCC 4.8. GCC 4.8 is still supported in v4.1 releases.

Author: kevinAlbs

CHANGELOG.md

@@ -12,6 +12,7 @@ Changes prior to 3.9.0 are documented as [release notes on GitHub](https://githu
 ### Fixed
 
 - `storage_engine() const` in `mongocxx::v_noabi::options::index` is correctly exported using mongocxx export macros instead of bsoncxx export macros.
+- Fix `-Wdeprecated-literal-operator` warning.
 
 ## 4.1.1
 

src/bsoncxx/include/bsoncxx/v_noabi/bsoncxx/json.hpp

@@ -82,7 +82,11 @@ BSONCXX_ABI_EXPORT_CDECL(document::value) from_json(stdx::string_view json);
 ///
 /// @throws bsoncxx::v_noabi::exception with error details if the conversion failed.
 ///
+#if defined(__GNUC__) && (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ <= 8)) && !defined(__clang__)
+BSONCXX_ABI_EXPORT_CDECL(document::value) operator"" _bson(char const* json, size_t len);
+#else
 BSONCXX_ABI_EXPORT_CDECL(document::value) operator""_bson(char const* json, size_t len);
+#endif // GCC <= 4.8
 
 } // namespace v_noabi
 } // namespace bsoncxx
@@ -92,7 +96,11 @@ namespace bsoncxx {
 using ::bsoncxx::v_noabi::from_json;
 using ::bsoncxx::v_noabi::to_json;
 
+#if defined(__GNUC__) && (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ <= 8)) && !defined(__clang__)
+using ::bsoncxx::v_noabi::operator"" _bson;
+#else
 using ::bsoncxx::v_noabi::operator""_bson;
+#endif // GCC <= 4.8
 
 } // namespace bsoncxx
 

src/bsoncxx/lib/bsoncxx/v_noabi/bsoncxx/json.cpp

@@ -107,7 +107,11 @@ document::value from_json(stdx::string_view json) {
     return document::value{buf, length, bson_free_deleter};
 }
 
+#if defined(__GNUC__) && (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ <= 8)) && !defined(__clang__)
+document::value operator"" _bson(char const* str, size_t len) {
+#else
 document::value operator""_bson(char const* str, size_t len) {
+#endif // GCC <= 4.8
     return from_json(stdx::string_view{str, len});
 }