-Wconversion warnings

[Aykelith]

I'm using g++ (i686-posix-dwarf-rev0, Built by MinGW-W64 project) 5.3.0 and g++ (i686-posix-dwarf-rev1, Built by MinGW-W64 project) 4.9.2 and I'm getting this:

In file included from ..\path\StateMachine.cpp:3:0:
../path/json/json.hpp: In instantiation of 'nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::type_data_t& nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::type_data_t::operator=(nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::value_t) [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator]':
../path/json/json.hpp:2037:22: required from 'nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::basic_json(nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>&&) [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator]'
../path/json/json.hpp:9568:98: required from here
../path/json/json.hpp:760:23: warning: conversion to 'unsigned char:4' from 'uint16_t {aka short unsigned int}' may alter its value [-Wconversion]
bits.type = static_cast<uint16_t>(rhs);
^
In file included from ..\path\StateMachine.cpp:3:0:
../path/json/json.hpp: In instantiation of 'nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::escape_string(const string_t&)::<lambda(char)> [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator]':
../path/json/json.hpp:6081:40: required from 'struct nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::escape_string(const string_t&) [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t = std::basic_string]::<lambda(char)>'
../path/json/json.hpp:6084:25: required from 'static nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::escape_string(const string_t&) [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t = std::basic_string]'
../path/json/json.hpp:6162:48: required from 'void nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::dump(std::ostream&, bool, unsigned int, unsigned int) const [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; std::ostream = std::basic_ostream]'
../path/json/json.hpp:2167:61: required from 'nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::dump(int) const [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t = std::basic_string]'
../path/json/json.hpp:9549:25: required from here
../path/json/json.hpp:6083:72: warning: conversion to 'char' from 'int' may alter its value [-Wconversion]
return (v < 10) ? ('0' + v) : ('a' + v - 10);
^
../path/json/json.hpp:6083:72: warning: conversion to 'char' from 'int' may alter its value [-Wconversion]
../path/json/json.hpp: In instantiation of 'static nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::escape_string(const string_t&) [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t = std::basic_string]':
../path/json/json.hpp:6162:48: required from 'void nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::dump(std::ostream&, bool, unsigned int, unsigned int) const [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; std::ostream = std::basic_ostream]'
../path/json/json.hpp:2167:61: required from 'nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::dump(int) const [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t = std::basic_string]'
../path/json/json.hpp:9549:25: required from here
../path/json/json.hpp:6088:51: warning: conversion to 'char' from 'int' may alter its value [-Wconversion]
{ 'u', '0', '0', hexify(c >> 4), hexify(c & 0x0f)
^
In file included from ..\path\StateMachine.cpp:3:0:
../path/json/json.hpp: In instantiation of 'nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::type_data_t::type_data_t(nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::value_t) [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator]':
../path/json/json.hpp:1060:5: required from 'nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType> nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::parser::parse() [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator]'
../path/json/json.hpp:5837:36: required from 'static nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType> nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::parse(const string_t&, nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::parser_callback_t) [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t = std::basic_string; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::parser_callback_t = std::function<bool(int, nlohmann::basic_json<>::parse_event_t, nlohmann::basic_json<>&)>]'
../path/json/json.hpp:9568:98: required from here
../path/json/json.hpp:768:23: warning: conversion to 'unsigned char:4' from 'uint16_t {aka short unsigned int}' may alter its value [-Wconversion]
bits.type = static_cast<uint16_t>(t);

[nlohmann]

Hi @Aykelith, thanks for reporting. As I do not have a Mingw compiler at hand, could you please try the code at https://github.com/nlohmann/json/tree/feature/issue239 which should have less/no warnings.

[Aykelith]

json.hpp: In instantiation of 'nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::type_data_t& nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::type_data_t::operator=(nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::value_t) [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator]':
json.hpp:2037:22: required from 'nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::basic_json(nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>&&) [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator]'
json.hpp:9570:98: required from here
json.hpp:760:23: warning: conversion to 'unsigned char:4' from 'uint16_t {aka short unsigned int}' may alter its value [-Wconversion]
bits.type = static_cast<uint16_t>(rhs);
^
json.hpp: In instantiation of 'nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::type_data_t::type_data_t(nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::value_t) [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator]':
json.hpp:1060:5: required from 'nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::value_type& nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::operator[](nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::size_type) [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::reference = nlohmann::basic_json<>&; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::value_type = nlohmann::basic_json<>; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::size_type = unsigned int]'
Platform\TerrainInfo.cpp:15:44: required from here
json.hpp:768:23: warning: conversion to 'unsigned char:4' from 'uint16_t {aka short unsigned int}' may alter its value [-Wconversion]
bits.type = static_cast<uint16_t>(t);
^
In file included from Platform\TerrainInfo.cpp:3:0:
json.hpp: In instantiation of 'nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::escape_string(const string_t&)::<lambda(int)> [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator]':
json.hpp:6081:46: required from 'struct nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::escape_string(const string_t&) [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t = std::basic_string]::<lambda(int)>'
json.hpp:6086:25: required from 'static nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::escape_string(const string_t&) [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t = std::basic_string]'
json.hpp:6164:48: required from 'void nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::dump(std::ostream&, bool, unsigned int, unsigned int) const [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; std::ostream = std::basic_ostream]'
json.hpp:2167:61: required from 'nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::dump(int) const [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t = std::basic_string]'
json.hpp:9551:25: required from here
json.hpp:6085:63: warning: conversion to 'char' from 'int' may alter its value [-Wconversion]
: ('a' + static_cast(v - 10));
^
json.hpp:6085:63: warning: conversion to 'char' from 'int' may alter its value [-Wconversion]

[nlohmann]

@Aykelith, thanks for checking! I made another change that should get rid of more warnings. Could you please try https://github.com/nlohmann/json/tree/feature/issue239 again?

[Aykelith]

In file included from Platform\TerrainInfo.cpp:3:0:
json/json.hpp: In instantiation of 'nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::escape_string(const string_t&)::<lambda(int)> [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator]':
json/json.hpp:6081:46: required from 'struct nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::escape_string(const string_t&) [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t = std::basic_string]::<lambda(int)>'
json/json.hpp:6086:25: required from 'static nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::escape_string(const string_t&) [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t = std::basic_string]'
json/json.hpp:6164:48: required from 'void nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::dump(std::ostream&, bool, unsigned int, unsigned int) const [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; std::ostream = std::basic_ostream]'
json/json.hpp:2167:61: required from 'nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::dump(int) const [with ObjectType = std::map; ArrayType = std::vector; StringType = std::basic_string; BooleanType = bool; NumberIntegerType = long long int; NumberUnsignedType = long long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; nlohmann::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType>::string_t = std::basic_string]'
json/json.hpp:9551:25: required from here
json/json.hpp:6085:72: warning: conversion to 'char' from 'int' may alter its value [-Wconversion]
: ('a' + static_cast((v - 10) & 0xff));
^
json/json.hpp:6085:72: warning: conversion to 'char' from 'int' may alter its value [-Wconversion]

[nlohmann]

@Aykelith - I made another attempt to fix the warning - see https://github.com/nlohmann/json/tree/feature/issue239.

[Aykelith]

No more warnings :D

[nlohmann]

Thanks for reporting and checking!