????? ???? ?????? ????? ???? ?????

??????? ?????? ?????? EasyBMP ??????? ????? ???. ??? ?? ???? ????? ?? Windows, MacOS, ???????? ?-iOS, ????? ???? ???? ????? ??????????. ????? ???? ??? ????? ??, EasyBMP ???? ??? ????. ????, ??? ?????? ???? ???? ??? ?? ???? ????? ???? ?? ????? BMP. ???? ??? ??????:

BMP Player::GetCurrentFrame()
{
    BMP frame;
    // Some processing here
    return Frame;
}

??? ???? ???? ?? ????? ??? ?????? ??????? (e.g. MingGW ???? ?DevCPP)

BMP frame = player->GetCurrentFrame();

??????? ???? ?????? ??????? ?? ?????? ?? ????? ctor ??? ??? ?? ????? ???? ????? ?? ?????????. The library's author decided to go with non-compliant copy ctor somehow.

// Doesn't work - compiler fails to find the copy ctor
BMP( BMP& Input );
// Should be: BMP(const BMP& Input );

?????? ????? ?? ?????? ??? ?? ?????? ?? "xxx ???? const ???????" ????? ??? ?????? ??????? ????? ????? ("Input") ???? ??????? ?const. ???? ?? ?? ??? ?? 2 ??????:

1) ???? ???? ?????? ?????? ???? ctor ?????? ??? ???? ??? constness ????? ctor ????? ??????:

BMP::BMP(const BMP& Input)
{
    BMP(const_cast<BMP&>(Input));
}

2) ???? ???? ???? ??????? const ??? ???????????????? ???:

int TellBitDepth( void ) const;
int TellWidth( void ) const;
int TellHeight( void ) const;
int TellNumberOfColors( void ) const;
int TellVerticalDPI( void ) const;
int TellHorizontalDPI( void ) const;
RGBApixel* operator()(int i,int j) const;
RGBApixel GetPixel( int i, int j ) const;
RGBApixel GetColor( int ColorNumber ) const;

????? ??????? ???? ?????, ???? ??? ?? ?TellHorizontalDPI() (????? const) ????? ??????? ??????. ??? ??????? ?? ??, ?????? ???? ?????:

mutable int XPelsPerMeter;
mutable int YPelsPerMeter;

This finally solved copy ctor problem.

???? ????? ?? ??????: ???? ????? ?? ??????? ?? ctor ????? ???? ?????? ?? ?? ?? ????????? ??? ????? ??? ???? ??????? ???. This also applied to the assignment operator.