Compile warnings on MSVC 14.2

[paamand]

After upgrading from Visual Studio 17 to 19 i get the following compile warnings:

Warning C26451 Arithmetic overflow: Using operator '-' on a 4 byte value and then casting the result to a 8 byte value. Cast the value to the wider type before calling operator '-' to avoid overflow (io.2).
.\nlohmann\detail\conversions\to_chars.hpp 993
(also line 997, 1007, 1009, 1017, 1021, 1036 and 1038)

Warning C26444 Avoid unnamed objects with custom construction and destruction (es.84).
.\nlohmann\detail\input\json_sax.hpp 443

Warning C28020 The expression '0<=_Param_(1)&&_Param_(1)<=400-1' is not true at this call.
.\nlohmann\detail\output\serializer.hpp 804

Warning C26451 Arithmetic overflow: Using operator '+' on a 4 byte value and then casting the result to a 8 byte value. Cast the value to the wider type before calling operator '+' to avoid overflow (io.2).
.\nlohmann\detail\output\serializer.hpp 810

Warning C26495 Variable 'nlohmann::basic_json<std::map,std::vector,std::basic_string<char,std::char_traits<char>,std::allocator<char> >,bool,__int64,unsigned __int64,double,std::allocator,nlohmann::adl_serializer>::m_type' is uninitialized. Always initialize a member variable (type.6).
.\nlohmann\json.hpp 1777

[stale]

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[dota17]

Bad bot

[dota17]

1. C26495 in json.hpp

Warning C26495 Variable 'nlohmann::basic_json<std::map,std::vector,std::basic_string<char,std::char_traits,std::allocator >,bool,__int64,unsigned __int64,double,std::allocator,nlohmann::adl_serializer>::m_type' is uninitialized. Always initialize a member variable (type.6).
.\nlohmann\json.hpp 1777

json/include/nlohmann/json.hpp

Line 6474 in 973c52d

value_t m_type = value_t::null;

Unfortunately, I didn't got this warning in my VS2019. And i think the value m_type has been initialized.

2. C26444 in json_sax.hpp

Warning C26444 Avoid unnamed objects with custom construction and destruction (es.84).
.\nlohmann\detail\input\json_sax.hpp 443

I think this is a C26444 false positive.

[nlohmann]

Any idea how to proceed here?

[bhardwajs]

@nlohmann - I can take a look and send PR. However, I will be using the latest VS 16.5.3. Would that be okay or do you want to check for the specific VS instance?

[ArtemSarmini]

VS 16.5 should be compatible with older 16.X.

[nlohmann]

Yes, PRs welcome!