std::vector operator[] problem

[asus1575]

Hi!

I'm getting this error and I don't understand why. I hope you can help me.


Matrix3f.h

#ifndef MATRIX3F_H
#define MATRIX3F_H
#include <vector>


class Matrix3f
{
    public:
        Matrix3f();

        Matrix3f (const std::vector<float>& content);

        Matrix3f(const Matrix3f& other);

        Matrix3f& operator=(const Matrix3f& other);


        std::vector<float> m_elements;
    protected:
    private:
};

#endif // MATRIX3F_H

Matrix3f.cpp

#include "Matrix3f.h"
Matrix3f::Matrix3f()
{}


Matrix3f::Matrix3f(const std::vector<float>& content)
{
    for(auto i =  m_elements.begin(); i!= m_elements.end(); i++)
        {
           m_elements[i] = content[i];
        }
}

Matrix3f::Matrix3f(const Matrix3f& other)
{
    for(auto i = other.m_elements.begin(); i!=other.m_elements.end(); i++)
        {
            m_elements[i] = other.m_elements.[i];
        }
}

Matrix3f& Matrix3f::operator=(const Matrix3f& other)
{
    if (this == &other) return *this;
    for(auto i = other.m_elements.begin(); i!=other.m_elements.end(); i++)
        {
            m_elements[i] = other.m_elements.[i];
        }

    return *this;
}

||=== Build: Debug in Math (compiler: GNU GCC Compiler) ===|

E:\Math\src\Matrix3f.cpp||In constructor 'Matrix3f::Matrix3f(const std::vector<float>&)':|
E:\Math\src\Matrix3f.cpp|6|warning: 'Matrix3f::m_elements' should be initialized in the member initialization list [-Weffc++]|
E:\Math\src\Matrix3f.cpp|10|error: no match for 'operator[]' in '((Matrix3f*)this)->Matrix3f::m_elements[i]'|
E:\Math\src\Matrix3f.cpp|10|note: candidates are:|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|750|note: std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::operator[](std::vector<_Tp, _Alloc>::size_type) [with _Tp = float; _Alloc = std::allocator<float>; std::vector<_Tp, _Alloc>::reference = float&; std::vector<_Tp, _Alloc>::size_type = unsigned int]|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|750|note:   no known conversion for argument 1 from '__gnu_cxx::__normal_iterator<float*, std::vector<float> >' to 'std::vector<float>::size_type {aka unsigned int}'|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|765|note: std::vector<_Tp, _Alloc>::const_reference std::vector<_Tp, _Alloc>::operator[](std::vector<_Tp, _Alloc>::size_type) const [with _Tp = float; _Alloc = std::allocator<float>; std::vector<_Tp, _Alloc>::const_reference = const float&; std::vector<_Tp, _Alloc>::size_type = unsigned int]|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|765|note:   no known conversion for argument 1 from '__gnu_cxx::__normal_iterator<float*, std::vector<float> >' to 'std::vector<float>::size_type {aka unsigned int}'|
E:\Math\src\Matrix3f.cpp|10|error: no match for 'operator[]' in 'content[i]'|
E:\Math\src\Matrix3f.cpp|10|note: candidates are:|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|750|note: std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::operator[](std::vector<_Tp, _Alloc>::size_type) [with _Tp = float; _Alloc = std::allocator<float>; std::vector<_Tp, _Alloc>::reference = float&; std::vector<_Tp, _Alloc>::size_type = unsigned int]|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|750|note:   no known conversion for argument 1 from '__gnu_cxx::__normal_iterator<float*, std::vector<float> >' to 'std::vector<float>::size_type {aka unsigned int}'|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|765|note: std::vector<_Tp, _Alloc>::const_reference std::vector<_Tp, _Alloc>::operator[](std::vector<_Tp, _Alloc>::size_type) const [with _Tp = float; _Alloc = std::allocator<float>; std::vector<_Tp, _Alloc>::const_reference = const float&; std::vector<_Tp, _Alloc>::size_type = unsigned int]|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|765|note:   no known conversion for argument 1 from '__gnu_cxx::__normal_iterator<float*, std::vector<float> >' to 'std::vector<float>::size_type {aka unsigned int}'|
E:\Math\src\Matrix3f.cpp|14|warning: 'Matrix3f::m_elements' should be initialized in the member initialization list [-Weffc++]|
E:\Math\src\Matrix3f.cpp|18|error: no match for 'operator[]' in '((Matrix3f*)this)->Matrix3f::m_elements[i]'|
E:\Math\src\Matrix3f.cpp|18|note: candidates are:|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|750|note: std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::operator[](std::vector<_Tp, _Alloc>::size_type) [with _Tp = float; _Alloc = std::allocator<float>; std::vector<_Tp, _Alloc>::reference = float&; std::vector<_Tp, _Alloc>::size_type = unsigned int]|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|750|note:   no known conversion for argument 1 from '__gnu_cxx::__normal_iterator<const float*, std::vector<float> >' to 'std::vector<float>::size_type {aka unsigned int}'|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|765|note: std::vector<_Tp, _Alloc>::const_reference std::vector<_Tp, _Alloc>::operator[](std::vector<_Tp, _Alloc>::size_type) const [with _Tp = float; _Alloc = std::allocator<float>; std::vector<_Tp, _Alloc>::const_reference = const float&; std::vector<_Tp, _Alloc>::size_type = unsigned int]|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|765|note:   no known conversion for argument 1 from '__gnu_cxx::__normal_iterator<const float*, std::vector<float> >' to 'std::vector<float>::size_type {aka unsigned int}'|
E:\Math\src\Matrix3f.cpp|18|error: expected unqualified-id before '[' token|
E:\Math\src\Matrix3f.cpp||In member function 'Matrix3f& Matrix3f::operator=(const Matrix3f&)':|
E:\Math\src\Matrix3f.cpp|27|error: no match for 'operator[]' in '((Matrix3f*)this)->Matrix3f::m_elements[i]'|
E:\Math\src\Matrix3f.cpp|27|note: candidates are:|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|750|note: std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::operator[](std::vector<_Tp, _Alloc>::size_type) [with _Tp = float; _Alloc = std::allocator<float>; std::vector<_Tp, _Alloc>::reference = float&; std::vector<_Tp, _Alloc>::size_type = unsigned int]|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|750|note:   no known conversion for argument 1 from '__gnu_cxx::__normal_iterator<const float*, std::vector<float> >' to 'std::vector<float>::size_type {aka unsigned int}'|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|765|note: std::vector<_Tp, _Alloc>::const_reference std::vector<_Tp, _Alloc>::operator[](std::vector<_Tp, _Alloc>::size_type) const [with _Tp = float; _Alloc = std::allocator<float>; std::vector<_Tp, _Alloc>::const_reference = const float&; std::vector<_Tp, _Alloc>::size_type = unsigned int]|
e:\program files (x86)\codeblocks\mingw\bin\..\lib\gcc\mingw32\4.7.1\include\c++\bits\stl_vector.h|765|note:   no known conversion for argument 1 from '__gnu_cxx::__normal_iterator<const float*, std::vector<float> >' to 'std::vector<float>::size_type {aka unsigned int}'|
E:\Math\src\Matrix3f.cpp|27|error: expected unqualified-id before '[' token|
||=== Build failed: 6 error(s), 2 warning(s) (0 minute(s), 0 second(s)) ===|

Thanks!

Asus.

[Cody0023]

Your vector has no size.

[asus1575]

Thanks for the answer!

Even if a give it a size with
m_elements.reserve(20000);

I'm still getting the same error.


Asus.

[helios]

reserve() doesn't change the size, it changes the capacity.

[Cody0023]

use vector.push_back(). Your vector has to have a size if its to be used with a subscript. So instead of m_elements[i]=data[i], do m_elements.push_back(data[i])

[asus1575]

Right. What should I do then?

I tried this:

Matrix3f::Matrix3f(const std::vector<float>& content):m_elements(9)
{
    for(auto i =  m_elements.begin(); i!= m_elements.end(); i++)
        {
           m_elements[i] = content[i];
        }
}

But I'm still getting the same error.

EDIT: I just read your messege Cody. That worked, thanks.

[Cody0023]

The vector is already defined. You would have to use the resize method to adjust the size of the vector.

Look at the different methods for the vector class

http://www.cplusplus.com/reference/vector/vector/