Mirror is a minimalistic C++20 reflection library. It contains utilities for counting the non-static data members in types, and for viewing objects as tuples.
Implementation uses the same basic idea as Antony Polukhin's magic_get, and has the same limitations.
Hopefully, this library will become obsolete by the time C++26 comes out.
The library consists of one module file in the src
directory. By default only
types with up to 32 non-static data members can be viewed as tuples. To increase
this number the generate.sh
script can be used (requires python3 and
clang-format).
For example, to increase the limit to 255, the following command can be executed in a terminal:
./generate.sh 255
To obtain the number of non-static data members in a type, use the
data_member_count
variable template:
struct custom_type {
int x, y, z;
float w;
};
static_assert(mirror::data_member_count<custom_type> == 4);
To view an object of some type as a tuple of references to its non-static data
members, use the reflect
function:
auto x = custom_type{1, 2, 3, 4.0f};
auto t = mirror::reflect(x);
// The following expression evaluates to true.
// (std::get<0>(t) == x.x) && (&(std::get<0>(t)) == &(x.x))
Copyright Nezametdinov E. Ildus 2023. Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt)