//
// Created by light on 19-11-3.
//
#include
using namespace std;
// non-explicit-one-argument ctor
class Fraction
{
public:
// non-explicit-one-argument ctor å¯ä»¥æŠŠåˆ«çš„东西转æ¢ä¸ºFractionè¿™ç§
Fraction(int num, int den = 1) : m_numerator(num), m_denominator(den) {}
Fraction operator+(const Fraction &f)
{
return Fraction(this->m_numerator + f.m_numerator);
}
void getNumAndDen()
{
cout << m_numerator << " " << m_denominator << endl;
}
private:
int m_numerator; // 分å
int m_denominator; // 分æ¯
};
// explicit-one-argument ctor
class Fraction1
{
public:
// explicit-one-argument ctor å¯ä»¥æŠŠåˆ«çš„东西转æ¢ä¸ºFractionè¿™ç§
explicit Fraction1(int num, int den = 1) : m_numerator(num), m_denominator(den) {}
Fraction1 operator+(const Fraction1 &f)
{
return Fraction1(this->m_numerator + f.m_numerator);
}
void getNumAndDen()
{
cout << m_numerator << " " << m_denominator << endl;
}
private:
int m_numerator; // 分å
int m_denominator; // 分æ¯
};
class P
{
public:
P(int a, int b)
{
cout << "P(int a,int b)\n";
}
P(int a, int b, int c)
{
cout << "non-explicit P(int a,int b,int c)\n";
}
explicit P(int a, int b, int c, int d)
{
cout << "explicit P(int a,int b,int c,int d)\n";
}
};
void fp(const P &)
{
}
int main()
{
Fraction f(3, 5);
Fraction ff = f + 3; // 会将3转æ¢ä¸º(3,1) éšå¼è½¬æ¢
ff.getNumAndDen();
// 如果ä¸æƒ³ç¼–译器进行éšå¼è½¬æ¢,å¯ä»¥åœ¨å‰é¢æ·»åŠ explicit关键å—
// c++2.0之å‰explicitåªç¦æ¢"å˜åœ¨å•ä¸€å®žå‚"转æ¢
// c++2.0之åŽexplicitå¯ä»¥è¿›åˆ¶"多个实å‚"转æ¢
// Fraction1 f1(3,5);
// Fraction1 f2 = f1+3; // 会将3转æ¢ä¸º(3,1) ä¸ä¼šéšå¼è½¬æ¢ error: no match for ‘operator+’ (operand types are ‘Fraction1’ and ‘int’)
// f2.getNumAndDen();
P p1 = {77, 5};
P p2 = {77, 5, 89};
// P p3 = {77, 5, 89,99}; //error: converting to ‘P’ from initializer list would use explicit constructor ‘P::P(int, int, int, int)’
return 0;
}