https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70632
Bug ID: 70632
Summary: Wrong function name resolution using variadic template
and additional template parameters
Product: gcc
Version: 5.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: grumpy76 at web dot de
Target Milestone: ---
GCC Version
--------------------
g++ (GCC) 4.9.2 20150212 (Red Hat 4.9.2-6) - devtoolset 3
g++ (GCC) 5.2.1 20150902 (Red Hat 5.2.1-2) - devtoolset 4
System
------
CentOS Linux release 7.2.1511 (Core)
Command line to compile
-----------------------
g++ -std=c++11 -Wall -Wextra -pedantic
Minimal code to reproduce
-------------------------
#include <iostream>
#include <sstream>
#include <string>
template<typename T>
std::ostringstream& appendToStream(std::ostringstream& stream, const T&
value) {
stream << value;
return stream;
}
template<typename T, typename... Args>
std::ostringstream& appendToStream(std::ostringstream& stream, const T&
value, Args... args) {
stream << value;
return appendToStream(stream, args...);
}
template<typename... Args>
std::string createMessage(Args... args) {
std::ostringstream x;
appendToStream(x, args...);
return x.str();
}
template<typename... Args>
std::string foo(int, Args... args) {
return std::string("foo with int: " + createMessage(args...));
}
template<typename... Args>
std::string foo(Args... args) {
return std::string("foo without int: " +
createMessage(args...));
}
template<typename T, typename... Args>
std::string bar(int, Args... args) {
return std::string("bar with int: " + createMessage(args...));
}
template<typename T, typename... Args>
std::string bar(Args... args) {
return std::string("bar without int: " +
createMessage(args...));
}
int main(int, char**) {
int i(-1);
std::cout << foo(i, "Hello ", "world") << std::endl;
std::cout << foo("Hello ", "world") << std::endl;
std::cout << bar<float>(i, "Hello ", "world") << std::endl;
std::cout << bar<float>("Hello ", "world") << std::endl;
}
Output is
---------
foo with int: Hello world
foo without int: Hello world
bar without int: -1Hello world
bar without int: Hello world
Output expected
---------------
foo with int: Hello world
foo without int: Hello world
bar with int: Hello world
bar without int: Hello world
Comments
--------
Code works as expected with
- g++ (GCC) 4.8.5 20150623 (Red Hat 4.8.5-4)
- clang version 3.4.2 (tags/RELEASE_34/dot2-final)
- clang version 3.8.0 (tags/RELEASE_380/final)
- msvc-14.0 (19.00.23918)
