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c++stlvectorwchar-t

how do I create a functioning vector<wchar_t> that has an erase(size_t pos) method?


I am creating a C++ wstring class for use with mingw version 4.3.0, cross-compiling for Win32. I want my string to work like std::string which means that I want an erase(int pos) method that erases a single element at position pos.

Here is my first attempt:

#include <wchar.h>
#include <iostream>
#include <vector>

class wstring : public std::vector<wchar_t>{
public:
    void erase(size_t where){
    erase(begin()+where);
    }
};

int main(int argc,char **argv) {
    wstring c1;
    c1.push_back(L'a');
    c1.push_back(L'b');
    c1.push_back(L'c');
    c1.erase(1);

    for(size_t i = 0;i<c1.size();i++){
    std::cout << "c1[" << i << "] = " << c1[i] << "\n";
    }
    return 0;
}

This looks like it should work to me, but I get this wacko compiler error when I try to compile it:

$ i386-mingw32-g++ x1.cpp
x1.cpp: In member function 'void wstring::erase(size_t)':
x1.cpp:8: error: no matching function for call to 'wstring::erase(__gnu_cxx::__normal_iterator<wchar_t*, std::vector<wchar_t, std::allocator<wchar_t> > >)'
x1.cpp:7: note: candidates are: void wstring::erase(size_t)
$ 

What's really weird is that if I take out the erase method and just inline the code, I have no problem:

#include <wchar.h>
#include <iostream>
#include <vector>

class wstring : public std::vector<wchar_t>{
};

int main(int argc,char **argv) {
    wstring c1;
    c1.push_back(L'a');
    c1.push_back(L'b');
    c1.push_back(L'c');
    c1.erase(c1.begin()+1);

    for(size_t i = 0;i<c1.size();i++){
    std::cout << "c1[" << i << "] = " << c1[i] << "\n";
    }
    return 0;
}

I'm mystified.


Solution

  • The answer to your particular question is to use std::vector<T>::erase( iterator ) instead of remove:

    std::vector<int> v;
    v.push_back( 1 );
    v.push_back( 2 );
    v.push_back( 3 );
    v.erase( v.begin()+1 ); // equivalent to v.remove( 1 )
    

    But I don't think that you are barking at the right tree. There is already a std::wstring in the standard library that is the instantiation of basic_string with wchar_t, and that will get as close as it can to std::string (which is an instantiation of the same template with char)