c++ - automatic decay of lambda to function pointer when passing to template function -

is there way make lambda decay pointer, without explicitly casting right signature? tidy code:

template<typename t> t call(t(*func)()){ return func(); } int ptr(){ return 0; } int main(){     auto ret1 = call(ptr);     auto ret2 = call((int(*)())([]{ return 0; }));     auto ret3 = call([]{ return 0; });  //won't compile } 

it's evident call call works if lambda decays pointer, i'm guessing that can happen after right function overload/template chosen. unfortunately can think of solutions involve templates make lambda with signature decay, i'm square one.

you can change lambda use unary + operator: +[]{ return 0; }

this works because unary plus can applied pointers, , trigger implicit conversion function pointer.