Templates stl映射的模板ostream运算符重载
水头Templates stl映射的模板ostream运算符重载,templates,map,namespaces,overloading,ostream,Templates,Map,Namespaces,Overloading,Ostream,水头 #include <algorithm> #include <map> #include <string> namespace ns { typedef std::map<std::string, int> StrIntMap; template<typename T1, typename T2> std::ostream &operator<&
#include <algorithm>
#include <map>
#include <string>
namespace ns
{
typedef std::map<std::string, int> StrIntMap;
template<typename T1, typename T2>
std::ostream &operator<<(std::ostream &stream, const std::map<T1, T2>& map);
};
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名称空间ns
{
typedef std::map StrIntMap;
模板
std::ostream&operator我将仅解释问题,但如果没有贵方的进一步信息,很难找到解决方案
第一个问题是操作符
#include "head.hpp"
template<typename T1>
std::ostream & ns::operator<<(std::ostream &stream, const ns::T1& map)
{
for (ns::T1::const_iterator it = map.begin();
it != map.end(); ++it)
{
stream << (*it).first << " --> " << (*it).second << std::endl;
}
return stream;
}
#include <map>
#include <string>
#include <iostream>
#include "head.hpp"
int main(int, char **)
{
ns::StrIntMap bla;
bla["one"] = 1;
bla["two"] = 2;
std::cout << bla << std::endl;
return (0);
}
main.cpp no match for 'operator<<' in 'std::cout << bla'
note C:\Dev-Cpp\include\c++\3.4.2\bits\ostream.tcc:63 candidates are: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>&(*)(std::basic_ostream<_CharT, _Traits>&)) [with _CharT = char, _Traits = std::char_traits<char>]
note C:\Dev-Cpp\include\c++\3.4.2\bits\ostream.tcc:63 std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ios<_CharT, _Traits>&(*)(std::basic_ios<_CharT, _Traits>&)) [with _CharT = char, _Traits = std::char_traits<char>]
note C:\Dev-Cpp\include\c++\3.4.2\bits\ostream.tcc:63 std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::ios_base&(*)(std::ios_base&)) [with _CharT = char, _Traits = std::char_traits<char>]
struct StrIntMap : std::map<std::string,int>
{
// C++11 allows you to inherit all ctors from the base class:
using std::map<std::string,int>::map;
};