Re: Obtaining function signature
On 10 Feb., 09:58, Carl Barron <cbarron...@adelphia.net> wrote:
template <class T> struct function_arity;
template <class R>
struct function_arity<R()> {static const int value = 0;};
// for N=1..N_max do
template <class R,class T1>
struct function_arity<R(T1)> {static const int value = 1;};
template <class R,class T1,class T2>
struct function_arity<R(T1,T2)> {static const int value = 2;};
// etc.
boost's preprocessor library can be used to automate this, but
you said no preprocessor stuff.
using boost function [which uses the preprocessor :)]
template <class F> struct function_arity
{
static const int value = boost::function<F>::arity;
};
but tr1::function does not provide this.
Once variadic templates are accepted, then we have a cool,
short, concise (have I forgotten any relevant attribute? ;-))
approach to realize this:
template <class T> struct function_arity;
template <class R, class... Ts>
struct function_arity<R(Ts...)> { static const std::size_t value =
sizeof...(Ts); };
Greetings from Bremen,
Daniel Kr?gler
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