You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
50 lines
1.3 KiB
50 lines
1.3 KiB
6 years ago
|
// Simple version of std::bind that doesn't support placeholders
|
||
|
|
|
||
|
|
#pragma once
|
||
|
|
|
||
|
|
#include <tuple>
|
||
|
|
#include <utility>
|
||
|
|
|
||
|
|
// __bind_call generates a list of integers 0 .. N-1 ...
|
||
|
|
template <int N, typename F, typename Res, typename TArgs, int... list>
|
||
|
|
struct __bind_call {
|
||
|
|
static Res call(F& f, TArgs& t) {
|
||
|
|
return __bind_call<N - 1, F, Res, TArgs, N - 1, list...>::call(f, t);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
// ... which the __bind_call base case unpacks to get a sequence of
|
||
|
|
// tuple indexes to pass to std::get to extract the saved arguments
|
||
|
|
// from the tuple t.
|
||
|
|
template <typename F, typename Res, typename TArgs, int... list>
|
||
|
|
struct __bind_call<0, F, Res, TArgs, list...> {
|
||
|
|
static Res call(F& f, TArgs& t) {
|
||
|
|
return f(std::get<list>(t)...);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
template <typename F, typename Res, typename... Args>
|
||
|
|
struct __bind_helper
|
||
|
|
{
|
||
|
|
typedef std::tuple<typename std::decay<Args>::type...> TArgs;
|
||
|
|
|
||
|
|
F f_;
|
||
|
|
TArgs args_;
|
||
|
|
|
||
|
|
__bind_helper(F&& f, Args&&... args) : f_(f), args_(args...) { }
|
||
|
|
|
||
|
|
Res operator()()
|
||
|
|
{
|
||
|
|
return __bind_call<sizeof...(Args), F, Res, TArgs>::
|
||
|
|
call(f_, args_);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
template <typename F, typename... Args>
|
||
|
|
auto bind_simple(F&& f, Args&&... args)
|
||
|
|
-> __bind_helper<F, decltype(f(args...)), Args...>
|
||
|
|
{
|
||
|
|
return __bind_helper<F, decltype(f(args...)), Args...>(
|
||
|
|
std::forward<F>(f), std::forward<Args>(args)...);
|
||
|
|
}
|