On Thursday, 24 December 2020 at 09:56:50 UTC, Ola Fosheim
Grøstad wrote:
[snip]
I don't use concepts yet as it is a very new C++ feature. The
following code does not work in XCode, although it probably
should according to cppreference. So take this with a grain of
salt (other variations should be possible):
namespace detail {
template<template<typename> typename F, class U>
constexpr void _is_instantiable(F<U> a){}
}
template<class T>
struct Foo{};
template<class T>
concept Fooish = requires(T a){
detail::_is_instantiable<Foo>(a);
};
That Foo-ish reminds me of something in D like
static if (__traits(compiles, {
auto temp = Foo!T.init;
}))
