All Questions
Tagged with forwarding c++11
19
questions
0
votes
1
answer
391
views
Can modern C++ compilers optimise the assignment operator for temporary variables?
Below is MyStruct class implementation which has default and copy constructors.
struct MyStruct {
MyStruct(const string& name) {
cout << "Basic constructor called" <&...
- 1,439
3
votes
1
answer
1k
views
Simulating std::forward with std::forward_as_tuple
Let's say I use std::forward_as_tuple to store the arguments of a function call in a tuple
auto args = std::forward_as_tuple(std::forward<Args>(args)...);
And then I pass this tuple by lvalue ...
- 21.3k
5
votes
1
answer
922
views
Identity function with perfect forwarding
I want to write a function identity which perfectly forwards its argument without any copy. I would write something like this
template< typename V >
inline V&& identity( V&& v ...
- 369
5
votes
2
answers
315
views
Selective forwarding function
The task is to create a single-argument function that forwards all types apart from one (Foo), which it converts (to Bar).
(Let us assume there exists a conversion from Foo to Bar).
Here is the usage ...
- 30.1k
0
votes
1
answer
215
views
C func to C++ instance-member trampoline with non-bijective argument type mapping
EDIT: I think I have cracked it, here
(Non bijective here means we may have arguments of type const char or char* both mapping to const std::string&.)*
NOTE: I've been working at this and asking ...
- 30.1k
1
vote
1
answer
731
views
Perfect forwarding for wrapper classes
I have for example a wrapper class:
template <typename T>
struct Wrapper {
T t;
};
And some proxy class that takes does something with T:
template <typename T>
struct Proxy {
T ...
user1447257
1
vote
1
answer
1k
views
C++: Forwarding the sum of parameter pack and a std::tuple/array [duplicate]
I want to implement something like the following member function (method), which is supposed to increase each argument by some summand (addend) corresponding to the argument index and forward it to ...
- 6,022
5
votes
3
answers
294
views
Is a C++ template able to "forward any class function" from parent class?
class Foo {
public:
void methodA();
};
class ManagedFoo {
Foo fooInst;
public:
void methodA() { doSomething(); fooInst.methodA();}
};
Now I want to make ManagedFoo as a template, managing any ...
- 67
1
vote
0
answers
541
views
C++ master/slave register model
I'm looking forward to implement a master/slave register model template for any type in C++. I've started with:
template <typename T>
struct Reg {
Reg() {}
Reg& operator = (const T&...
- 46
5
votes
1
answer
1k
views
std::forward of rvalue ref to lambda?
Consider the following two snippets:
Exhibit A:
template<typename CalcFuncT>
int perform_calc(CalcFuncT&& calcfunc)
{
precalc();
int const calc = calcfunc();
postcalc();
...
- 67.7k
8
votes
2
answers
283
views
Deducing knowledge of original types, whilst simultaneously forwarding
Summary: I want to end up with a function that deduces the exact types it was called with and takes (e.g.) a tuple that forwards them (the types of which will be different from the exact types the ...
- 88.3k
177
votes
3
answers
85k
views
When to use std::forward to forward arguments?
C++0x shows an example of using std::forward:
template<class T>
void foo(T&& arg)
{
bar(std::forward<T>(arg));
}
When is it advantageous to use std::forward, always?
Also, it ...
- 9,595
0
votes
1
answer
266
views
Is this variadic template argument deduction correct?
I've been experimenting with variadic templates and argument forwarding. I think I've found some inconsistent behaviour.
To illustrate, this program:
#include <iostream>
#include <typeinfo&...
- 32.9k
5
votes
3
answers
945
views
Perfect forwarding
If we have the following:
template <class T>
struct B{
T data;
}
struct A{
int data_array[100];
}
int main()
{
A x;
const A x_const;
auto y1 = f(A());
auto y2 = f(x);
auto y3 = ...
- 22.9k
52
votes
2
answers
20k
views
C++11 use-case for piecewise_construct of pair and tuple?
In N3059 I found the description of piecewise construction of pairs (and tuples) (and it is in the new Standard).
But I can not see when I should use it. I found discussions about emplace and non-...
- 22k