Questions tagged [result-of]

std::result_of is a C++11 metafunction that provides the result of calling a function type with a given set of argument types.

The class template std::result_of is defined in the C++11 standard library and is a type transformation trait i.e. a metafunction that takes one type and produces another type.

The nested type std::result_of<F(A, B, C)>::type is a typedef for the type that would be returned by the expression f(a, b, c) for a callable object f of type F and arguments of types A, B and C.

50 questions

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c++ how to define a std::result_of that can handle R is void

When i am using std::result_of like this: template class Task { //... template auto Then(F&& f) -> Task::type(Args...)> { //... } …

asked Sep 10 '18 at 08:14

D.pz

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2 answers

C++11: std::result_of<> template argument vs std::function<>

I did do some research on std::result_of<>, and am aware how it's used on a high level, but am still pretty confused on this magical thing. So, if I understand it correctly, the form R (Args..) should be interpreted by the compiler as a function…

c++ c++11 std-function result-of

asked Jun 13 '18 at 04:43

Dejavu

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Using std::result_of<> for member method of member type

I am working with a HashMap type that does not specify its KeyType as a public member, only the ValueType. A way to retrieve the KeyType would be to use std::result_of with the HashMap<>::Entry::GetKey() method. I can't get it to work in a template…

c++ templates typename result-of

asked Apr 27 '18 at 18:20

Niklas R

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get resulting type of std::bind

I'm trying to get the resulting type of std::bind in combination with a lambda. I've tried the following two: template typename std::result_of func(F f, uint i); This doesn't work for whatever reason. I've also tried…

c++ decltype result-of

asked Jan 11 '18 at 19:21

user3617992

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1 answer

no type named "type" in "std::result_of" ; get return type from overloading functions

I am learning how to get type of the return value of overloaded function test() vs test(double). I modified code from a SO answer (by chris). #include #include int test(); double test(double x); template

c++11 variadic-templates overloading decltype result-of

asked Feb 16 '17 at 09:27

javaLover

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Need ‘typename’ before ‘std::result_of<_Signature>::type’ because ‘std::result_of<_Signature>’ is a dependent scope

I can't any good solution. I have piece of code: #include #include #include #include #include #include #include #include #include #include…

c++ c++11 templates gcc result-of

asked Oct 15 '16 at 08:52

Pingwin Tux

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3 answers

C++11 result_of deducing my function type failed

I was trying a program below: #include using namespace std; template ::type> R call(F& f) { return f(); } int answer() { return 42; } int main() { call(answer); return…

function c++11 return result-of

asked Jun 29 '16 at 01:42

Troskyvs

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C++11 applies result_of on member function, failed, why?

I've got the following code as an experiment: int f1() { return 0; } struct Bar { Bar() = delete; int f() { return 0; } int operator()() { return 1; } }; int main() { decltype(f1()) x = 3;//f1() is expression …

c++ c++11 types decltype result-of

asked Jun 21 '16 at 09:33

Hind Forsum

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std::result_of on std::bind does not compile on clang++ 3.4

The following code compiles using g++-4.8 but it doesn't when using clang 3.4. #include #include struct A { template bool operator()( //const Continuation & continuation …

c++ c++11 bind clang++ result-of

asked Mar 24 '14 at 14:37

user2590425

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1 answer

Workaround for VS 2013 SFINAE deficiencies

I'm trying to fix up a library (entityx) that does not currently compile on Windows using VS 2013. It compiles fine on Linux with gcc and also on Windows with MinGW. It seems the problem is with SFINAE - I guess VS 2013 doesn't properly ignore…

c++ c++11 visual-studio-2013 sfinae result-of

asked Feb 11 '14 at 02:56

Jarrett

1,767
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2 answers

Result type of a class method?

Consider the following example: #include #include #include #include // Array: I cannot modify this class template class Array { public: Array() : _data()…

c++ templates c++11 typetraits result-of

asked Dec 24 '12 at 05:09

Vincent

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why std::result_of can't accept function type?

I have this code int f(int i){ return i; } int main(){ cout << std::boolalpha; using f_1 = decltype(f); using f_2 = decltype((f)); cout << is_same, int>::value<< endl; // ERROR cout <<…

c++ templates typetraits result-of

asked Jan 24 '23 at 05:43

Kevin eyeson

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1 answer

std::result_of syntax kerfuffle

I have the following (CUDA) function: __device__ auto foo(my_class& x, my_function_ptr_type y ) { return [gen](my_class& x) { return x.set_y(y); }; } And I want typedef its return value's type. I've fiddling with the std::result_of syntax, and…

c++ c++11 cuda result-of

asked Jan 01 '20 at 14:40

einpoklum

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2 answers

Can I get the Return Type of a Function From a Signature?

So I have a ton of functions similar to these: template bool Zero(const T, const T, const T); template T One(const T, const T, const T, bool); template T Three(const T, const T, const T, const T, const T, const…

c++ metaprogramming return-type decltype result-of

asked Mar 04 '19 at 13:51

Jonathan Mee

37,899
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0 answers

How can I use std::result_of to return the function type instead of void

I am trying to get the return type of a function that I bind in. In this instance I was expecting to see the return type of GetFactorialResult (int). #include #include #include namespace { const…

c++11 templates std auto result-of

asked Jun 04 '18 at 15:17

Jon

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