STL remove_if function

[Paavo K]

Hi, can anyone tell what is wrong with following code :

//..Code

class removeTest
{
public:
bool operator()(map<int, string>::value_type &d) const
{
// Just returning false to simplify code..
return false;
}
};

void testFunction()
{
map<int, string> *m = new map<int, string>;

if(m->empty() == false)
{

m->erase(
remove_if(m->begin(),
m->end(),
removeTest()),
m->>end()
);

}
else cout<<"\n Nothing to remove \n";
}
Visual C++ compiler return this message :

c:\microsoft visual studio\vc98\include\algorithm(317) :
error C2582: 'std::pair<int const ,class std::basic_string<char,struct
std::char_traits<char>,class std::allocator<char> > >' : 'operator ='
function is unavailable

Thanks in advance!

[David Harmon]

On Tue, 17 Feb 2004 19:09:13 +0200 in comp.lang.c++, Paavo K
<ko******@students.oamk.fi> was alleged to have written:

map<int, string> *m = new map<int, string>; .... remove_if(m->begin(),
m->end(),
removeTest()),
m->>end()
);
You cannot use std::remove_if against a std::map. remove_if reorders
elements (perhaps surprisingly, it does not really remove anything) and
elements of a map cannot be reordered.
Visual C++ compiler return this message :

c:\microsoft visual studio\vc98\include\algorithm(317) :
error C2582: 'std::pair<int const ,class std::basic_string<char,struct
std::char_traits<char>,class std::allocator<char> > >' : 'operator ='
function is unavailable

Notice the "const" in the above message. You cannot assign to a
std::pair with a const member.