compile template question
chenzero
chenzero@netease.com
Fri Dec 2 12:13:00 GMT 2016
Hello,
I have following code,
in gcc 4.8.4, the code can NOT compile, because of an error:
error: need âtypenameâ before âstd::map<K, V>::iteratorâ because
âstd::map<K, V>â is a dependent scope
however, I can compile the same code in other C++ compiler(borland c++),
whether there are some differences between gcc template syntax?
Thank you very much!
c.z.
// code
//-----------------------------------------------------------
#include <stdio.h>
#include <map>
#include <vector>
using namespace std;
/**
* get all keys of the map into vector
*/
template<typename K, typename V>
static void getKeySet(std::map<K,V>& m, std::vector<K>& ks) {
std::map<K,V>::iterator iter = m.begin();
for(iter=m.begin();iter!=m.end();iter++) {
ks.push_back(iter->first);
}
}
int main() {
map<int,int> m1;
//m1[1] = 1;
vector<int> ks;
getKeySet(m1, ks);
printf("key size: %d\n", ks.size());
return 0;
}
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