（C ++）没有构造函数的实例…与参数列表匹配

Question

Just began learning C++ and i'm working on an assignment to display colored symbols and text in the console. For this I am creating a pen object, however I am getting an error of 'No instance of constructor matches the argument list' however I believe I am passing the correct parameters.

I've been scratching my head and stressing about this for over 2 hours now, I am hoping that someone could pick up where I have gone wrong and point me in the right direction.

Thanks.

Main method:

//#include "stdafx.h"
#include <iostream>
#include "tui.h"

using namespace std;
using namespace textUserInterface;

int main()
{

cout << "Testing..." << endl;

byte testColor = color::red;
pen myPen(color::red, color::black, "@", true); //Error on this construction

return 0;
}

Tui header file:

#ifndef TUI_H
#define TUI_H

typedef unsigned char byte;

namespace textUserInterface {

class tui
{
public:
    tui();
protected:
private:
};

class color
{
public:
    static const byte magenta = 5;
    static const byte yellow = 3;
    static const byte red = 1;
    static const byte white = 7;
    static const byte green = 2;
    static const byte blue = 4;
    static const byte black = 0;
    static const byte system_default = 0;
private:
    color();
};

class pen
{
public:
    pen(byte _foreground, byte _background, char _character, bool _isBright);
private:
    byte foreground;
    byte background;
    char character;
    bool isBright;
};
}
#endif

Tui cpp file:

#include <iostream>
#include "tui.h"

using namespace std;
using namespace textUserInterface;

tui::tui()
{

}

pen::pen(byte _foreground, byte _background, char _character, bool _isBright)
: foreground(_foreground), background(_background), character(_character), isBright(_isBright)
{

}

Answer 1

The problem is the constructor takes a char but you are passing a C-style string "@" . You need to use single-quotes to get a single char , ie '@' .

If you have a good compiler, it should have given you an error message along the lines of "Cannot convert from const char* to char in argument 3."

Answer 2

pen myPen(color::red, color::black, "@", true);

"@" is a const char[2] which you try to pass in as a char argument.

You probably meant '@' :

pen myPen(color::red, color::black, '@', true);