Linux compilation error - cannot convert type ‘string’ to type ‘string&&’, when inserting into a map containing string. The same is building fine on Windows. My use case:
void insertIf(std::string str1, int value, std::map<std::string,int> &myMap) const
{
if(value == 1)
{
myMap.insert(std::make_pair<std::string, int>(str1, value));
}
}
That's because std::make_pair takes forwarding reference as parameter. You should use std::make_pair with a deducing context and the constructor of std::pair when you want to specify template parameter explicitly.
Here's are your choices :
make_pair:
void insertIf(std::string str1, int value, std::map<std::string,int>& myMap) {
if(value == 1 {
myMap.insert(std::make_pair(str1, value));
}
}
pair constructor
void insertIf(std::string str1, int value, std::map<std::string,int>& myMap) {
if(value == 1 {
myMap.insert(std::pair<std::string, int>(str1, value));
}
}
Even better, emplace:
void insertIf(std::string str1, int value, std::map<std::string,int>& myMap) {
if(value == 1 {
myMap.emplace(str1, value);
}
}
If you really want to use std::make_pair with explicit parameters, you can specify the value category in the template parameter but I advise you to not do this, it kinda defeats the whole purpose of std::make_pair :
void insertIf(std::string str1, int value, std::map<std::string,int>& myMap) {
if(value == 1 {
myMap.insert(std::make_pair<std::string&, int&>(str1, value));
}
}
Edit: it worked on Windows because you must use an outdated version of VS, which don't support forwarding reference yet.
arg1.insert(std::make_pair<std::string,int>(str1,int1));<--))