/* Someone please help me. As C++ is not a po- pular programming language, it is hard to find courses for advanced C++ learners. I am learning how to use std::async but to no avail. There are very few tutorials on this topic on YouTube. I am also having problems with this annoyi- ng << operator overloading function. Please help T_T. Also, you cannot compile this using SL bec- ause "windows.h" is not supported. Use Cxx droid or CodeBlocks or some other non-web compiler */ #include #include #include #include #include #include #include #include using namespace std; // coloured text class // only focus at the << overloading friend function class fancy { public: // where actions will be performed on string content; // constructor fancy( string R = "", string c = "white" ){ content = R; // --> all duplicate code, just use your existing setColor() method //int *flag = new int; //*flag = 0; //for ( int i = 0;i < 16; i++ ){ // if ( c == colors[ i ] ) { // _color = i; // flag = 1; // break; // } //} //if ( flag == 0 ) // _color = 15; //delete flag; //_color++; this->setColor( c ); } // destructor // --> will be added automatically by the compiler anyway //~fancy(){ // //} // find out length // --> does not modify object, should be const const int length() const { return content.length(); } // similar to "std::substr()" method // --> does not modify object, should be const fancy substr( int _start, int _end ) const { fancy res( "",colors[ _color ] ); res.content = content.substr( _start,_end ); return res; } // change color of string on console void setColor( string c ) { // --> no need for dynamic allocation //int *flag = new int; //*flag = 0; int flag = 0; for ( int i = 0; i < 16; i++ ) { if ( c == colors[ i ] ){ _color = i; flag = 1; break; } } if ( flag == 0 ) _color = 15; //delete flag; _color++; } // all operator overloading methods // here // --> does not modify parameter, should be const // --> does not modify object, should be const fancy operator +( const fancy& ) const; // --> typically returns self-reference for chained calls // --> does not modify parameter, should be const fancy& operator +=( const fancy& ); // --> same as above fancy& operator *=( int num ) { string accum; for ( int i = 1; i < num; i++ ) accum += content; content = accum; return *this; } // --> does not modify object, should be const fancy operator +( string ) const; // --> typically returns self-reference for chained calls fancy& operator += ( string ); // --> same as above fancy& operator =( string p ){ this->content = p; return *this; } // --> do not modify object, should be const string operator[]( int _index ) const ; fancy operator*( int num ) const ; //problem here /* I tried to do friend ostream operator& << (ostream &output, fancy &p); but it gives errors as it said : "ostream was already destructed" */ // --> should return ostream& for chained calls // --> does not modify fancy parameter, should be const //friend fancy operator << ( ostream &output, fancy &p ); friend ostream& operator << ( ostream&, const fancy& ); // --> should return istream& for chained calls //friend fancy operator >> ( ostream &input, fancy & p); friend istream& operator >> ( istream&, fancy& ); private: static HANDLE h; static string colors[ 16 ]; int _color; }; string fancy::operator[]( int _index ) const { string res; stringstream ss; //convert char to string ss << content[ _index ]; ss >> res; return res; } //cout << overloading ostream& operator << ( ostream &output, const fancy &p ) { SetConsoleTextAttribute( fancy::h, p._color ); output << p.content; SetConsoleTextAttribute( fancy::h, 15 ); return output; } //cin >> istream& operator >> ( istream &input, fancy &p ) { input >> p.content; return input; } fancy& fancy::operator += ( const fancy &A ) { this->content += A.content; return *this; } fancy fancy::operator *( int num ) const { fancy res( "", colors[ _color - 1 ] ); for ( int i = 0; i < num; i++ ) res.content += content; return res; } fancy fancy::operator +( const fancy &A ) const { fancy res; res.content = this->content + A.content; return res; } fancy& fancy::operator +=( string p ) { this->content += p; return *this; } fancy fancy::operator +( string p ) const { fancy res( this->content + p ); return res; } // static objects. Ignore them HANDLE fancy::h = GetStdHandle( STD_OUTPUT_HANDLE ); string fancy::colors[ 16 ] = { "blue", "darkgreen", "cyan", "crimson", "pink", "darkyellow", "lightgrey", "grey", "navyblue", "green", "cyan", "red", "magenta", "yellow", "white" }; // mutex object // I dont fucking know what does this do //mutex mu; // function for printing the images // --> just pass by (const) reference instead of a pointer // --> most of the errors here resulted in not dereferencing the pointer void printImage( const vector>& img, int height ) { int width = img[ 0 ].size(); // make sure the array cannot be accessed more than once at the same time //lock_guard lock(mu); // iterate through every pixel for ( int i = 0; i < height; i++ ) { for ( int j = 0; j < width; j++ ) { cout << img[ i ][ j ]; // print each pixel } cout << endl; // new line } // return void return; } int main( int argc, char *argv[] ) { //colored strings fancy r( "█","crimson" ), y( "█","darkyellow" ), b( "█","cyan" ), R( "█","white" ); //image 1 vector> cccp = { {b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b}, {b,b,R,R,R,b,b,b,R,R,R,b,b,b,R,R,R,b,b,R,R,R,R,R}, {b,R,R,b,b,R,b,R,R,b,b,R,b,R,R,b,b,R,b,R,b,b,b,R}, {b,R,R,b,b,b,b,R,R,b,b,b,b,R,R,b,b,b,b,R,b,b,b,R}, {b,R,R,b,b,b,b,R,R,b,b,b,b,R,R,b,b,b,b,R,R,R,R,R}, {b,R,R,b,b,R,b,R,R,b,b,R,b,R,R,b,b,R,b,R,b,b,b,b}, {b,b,R,R,R,b,b,b,R,R,R,b,b,b,R,R,R,b,b,R,b,b,b,b}, {b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b,b} }; //image 2 vector> sovietFlag = { {r,r,r,r,r,r,r,r,r,r}, {r,r,r,y,r,r,r,r,r,r}, {r,r,y,y,y,r,y,r,r,r}, {r,y,y,y,r,r,r,y,r,r}, {r,r,y,r,y,r,r,y,r,r}, {r,r,r,r,r,y,r,y,r,r}, {r,r,r,y,r,r,y,y,r,r}, {r,r,y,r,y,y,y,y,r,r}, {r,y,r,r,r,r,r,r,y,r}, {r,r,r,r,r,r,r,r,r,r} }; //collection of all images vector>> images; //I dont know what the actual fuck is this vector is for // vector> m_Futures; //append images images.push_back( cccp ); images.push_back( sovietFlag ); //create thread for each image for ( const auto &image : images ) { //m_Futures.push_back(async(launch::async,printImage,image,image.size())); printImage( image, image.size() ); } //I am not so sure if this gives errors //for (const auto&fut:m_Futures){ //activate thread? // fut.get(); //} return 0; }

[Q&A] Coloured Images