Template argument deduction is a compiler attempt to deduce template arguments when some are omitted.
Questions tagged [template-argument-deduction]
692 questions
0
votes
2 answers
Integral types messing up with sizeof(T)
class Foo
{
public:
Foo(const void* data) : m_dataPtr(data) {}
template
const T Get() {
const T* readPoint = static_cast(m_dataPtr);
m_dataPtr = (const char *) m_dataPtr + sizeof(T);
return…
ReBirTH
- 91
- 7
0
votes
3 answers
C++11, type deduction of derived class in static method
Minimal example:
class Task
{
public:
template
static T* make(Args... args) {
return new T(args...);
}
}
template
class MyTask : public Task
{
public:
MyTask(A a, B b, C…
mikepurvis
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0
votes
1 answer
Template argument deduction fails on lambda using tuple
I'm trying to make a query function that lets me query an STL container for certain element characteristics, and then return the result set. It's really just syntactic sugar around normal STL operations (specifically, copy_if and a…
Badmanchild
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0
votes
2 answers
function template argument deduction in a class
I have always thought that function template argument deduction can work only for pure function like below and not for classes.
template
T foo(T2 a, T3 b)
{
T o;
//..do something
return o;
}
Today Just by…
Abruzzo Forte e Gentile
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0
votes
2 answers
Partial template specialization by overloading
I created a simple round template function with an extra template argument that defines the type the rounded value needs to be casted to before returning.
template
T round(U val) {
T result;
if (val >= 0)
…
Didii
- 1,194
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- 36
0
votes
2 answers
Resolving ambiguous call in template argument deduction
A typical function template signature:
template
T fn(Iterator first, Iterator last, T init)
{
T result;
// ...
return result;
}
The problem is, when I call it like this:
std::vector…
Charles Pehlivanian
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0
votes
0 answers
Is template template parametrs supported for function supported in new C++ standards?
I found the following statement in the book C++ Template: The complete Guide:
Template template parameters for function templates are not allowed.
But he following piece of code compiles and run for me.
template< typename T, template
sajas
- 1,599
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0
votes
3 answers
Function template cannot deduce type if types T and U are the same
This question stems from an answer I received yesterday. For the following function, I am getting the error couldn't deduce template parameter ‘V’ if both T and U are std::complex. If T and U are different, the function compiles and works as…
OSE
- 986
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0
votes
4 answers
Can I write something that uses type deduction as in make_tuple?
I can either write make_tuple(1,true) or write make_tuple(1,true) and the compiler will deduce it's types. Is this ability available for code I write or is it somehow built into the compiler to which I can't access?
Fred Finkle
- 1,947
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-1
votes
1 answer
variadic template argument deduction, cannot match struct in argument
I can't work this out.
I have a template class integer that has in its template parameter its value, and I want to add together n integers of this class. I can successfully get the int value from the class in the base case, but it fails…
user18263309
- 23
- 4
-1
votes
1 answer
Determining the type of the template parameter method argument
There are many IEnumXXXX type COM interfaces that have a pure virtual method Next, like this:
IEnumString : IUnknown {
...
virtual HRESULT Next(ULONG, LPOLESTR*, ULONG*) = 0;
...
};
IEnumGUID : IUnknown {
...
virtual HRESULT Next(ULONG, GUID*,…
vlasovdl
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- 2
-1
votes
2 answers
Template argument deduction Doesn't Work for Function Template
I am trying to understand how template argument deduction works in C++. And so writing out different examples. One such example which doesn't work and i can't understand why is given below:
#include
template
void func…
Jason
- 36,170
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-1
votes
2 answers
Template deduction guide fails with 'too many initializers' error
I was reading on template deduction then tried to create one.
as follows:-
#include
#include
using namespace std;
template struct deducted{
};
//Deduction guide
template…
D. Sikilai
- 467
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- 17
-2
votes
1 answer
C++ How to create a class template that allows no template arguments
I apologize if my title is confusing. What I'm trying to do is create a class template implementing the std::map from scratch. What I want to achieve is to not use specific data types in the template arguments. Please see the code below:
#include…
Mr George
- 39
- 7
-2
votes
2 answers
Any way to define a "doubling" operator?
I have a class that represents a quantity that can only take on integer or half-integer values, and so stores its value internally as an integer that is twice the value. That is: a value of 0.5 is stored as 1, 1 as 2, 1.5 as 3, etc. Let's call it…
DanielGr
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