mlimber wrote:
Victor Bazarov wrote:
mlimber wrote:
Any ideas why this code:
#include <vector>
using namespace std;
struct Foo
{
void Bar( int, int, int );
template<typename T>
void Bar(
typename vector<T>::const_iterator,
typename vector<T>::const_iterator,
int );
};
void Baz()
{
Foo foo;
const vector<int> v( 10u );
foo.Bar( v.begin(), v.end(), 42 );
}
generates this compile-time error:
"ComeauTest.c", line 20: error: no instance of overloaded function
"Foo::Bar" matches the argument list
The argument types that you used are: (
std::vector<int,std::allocator<int>>::const_iterator,
std::vector<int,std::allocator<int>>::const_iterator,
int)
object type is: Foo
foo.Bar( v.begin(), v.end(), 42 );
^
I expected the compiler to select the templatized overload.
The compiler cannot deduce that 'T' is 'int' from
vector<int>::const_iterator. It's not one of "deducible contexts".
Can you elaborate and perhaps supply a work-around (other than
explicit qualification, preferably).
Elaborate? Look in the Standard, 14.8.2.4/9, or in the news archives.
Workaround, eh? Try:
...
template<class I> void Bar(I, I, int);
In that case your 'I' should be 'std::vector<int>::const_iterator', and
you can then extract 'int' from it using 'value_type' or some such.
#include <vector>
using namespace std;
struct Foo
{
void Bar( int, int, int );
template<typename I> void Bar(I, I, int);
};
void Baz()
{
Foo foo;
const vector<int> v( 10u );
foo.Bar( v.begin(), v.end(), 42 );
foo.Bar( 1,2,3 );
}
The code above compiles fine, but it's up to you to see if it suits
your purposes.
Ok, thanks. For reference, I used std::iterator_traits to get the