我需要预处理这段代码:
line (0,0) (5,5)
其中(0,0)表示开始x和y坐标,第二个(5,5)表示结束x和y坐标。
我能够使用
获取起始坐标#define line(x1,y1) myArray->shapes.push_back(new Line(x1,y1));
如何处理第二个括号?
答案 0 :(得分:7)
如下所示:
struct LineCreator {
LineCreator(type_of_shapes &shapes, int x1, int y1)
: shapes_(shapes), x1_(x1), y1_(y1)
{}
void operator() (int x2, int y2) {
shapes_.push_back(new Line(x1_, y1_, x2, y2));
}
private:
type_of_shapes &shapes_;
int x1_, y1_;
};
#define line(x, y) LineCreator(myArray->shapes, (x), (y))
答案 1 :(得分:1)
将其更改为:
line (0,0,5,5)
现在您可以构建以下宏:
#define line(x1,y1,x2,y2) myArray->shapes.push_back(new Line(x1,y1)); \
myArray->shapes.push_back(new Line(x2,y2));