用C ++初始化一个向量pf点

Question

Point P0(0,0), P1(3, 4), P2(-50,-3), P3(2,0); //Input  Points (fine)
std::vector<Point>  Points(P0,P1, P2 ,P3); (not fine)

This does not seem to work. How do I initialize points vector to the values above? Or is there an easier way to do this?

Answer 1

如果您使用的是c ++ 11，则可以使用大括号来内联声明向量。

std::vector<Point> Points {P0, P1, P2, P3};

Answer 2

Try the following code (not tested):

Point P0(0,0), P1(3, 4), P2(-50,-3), P3(2,0); //Input  Points (fine)
std::vector<Point> Points;

Points.push_back(P0);
Points.push_back(P1);
Points.push_back(P2);
Points.push_back(P3);

Answer 3

There is no need to define objects of type Point that to define the vector. You could write

std::vector<Point>  Points{ { 0, 0 }, { 3, 4 }, { -50,-3 }, { 2, 0 } };

provided that your compiler supports the brace initialization. Or you could define an array of Point and use it to initialize the vector. For example

#include <vector>
#include <iterator>
//,,,
Point a[] = { Point( 0, 0 ), Point( 3, 4 ), Point( -50,-3 ), Point( 2, 0 ) };
std::vector<Point>  Points( std::begin( a ), std::end( a ) ) ;

This code will be compiled by MS VC++ 2010.