eve::common_type< Ts > Struct Template Reference

Computes a type that can represent all values in a list of types. More...

#include <eve/traits/common_type.hpp>

Detailed Description

template<typename ... Ts>
struct eve::common_type< Ts >

Required header: #include <eve/traits/common_type.hpp>

Similar to std::common_type.

We cannot use std::common_type because it tends to return a bigger type: For example: std::int16_t, std::int8_t will return std::int32_t: https://godbolt.org/z/vjf9c45E5

We also do not follow standard promotion rules: std::common_type_t<std::int16_t, std::uint16_t> is std::int32_t BUT: std::common_type_t<std::int32_t, std::uint32_t> is std::uint32_t We always do like 32 bit one: - eve::common_type_t<std::int16_t, std::uint16_t> is std::uint16_t

For functors from eve/constant support is incomplete: FIX-#941. For now, we just skip them.

NOTE: for signed unsigned of the same size we return unsigned of this size (same as std).

For product types TODO: FIX-#905 Right now we have some simplified logic.