"error: expected expression" when compiling from command line but not from Xcode

Question

I compiled the following code snippet with clang++ (700.1.76) and Xcode 7.1 separately.

#include <iostream>
#include <string>

using namespace std;

class Point {
private:
    int x;
    int y;
public:
    Point(int x1 = 0, int y1 = 0) {
        x = x1;
        y = y1;
    }
    string display() {
        return "(" + to_string(x) + ", " + to_string(y) + ")";
    }
};

class Shape {
private:
    Point bottomLeft;
    Point upperRight;
public:
    Shape(Point bottomLeft1, Point upperRight1) {
        bottomLeft = bottomLeft1;
        upperRight = upperRight1;
    }
    Point getBottomLeft() {
        return bottomLeft;
    }
};

int main(int argc, char const *argv[]) {
    Point p1(1, 2);
    Point p2(3, 4);
    Shape s1(p1, p2);
    Shape s2({1, 2}, {3, 4});
    cout << s1.getBottomLeft().display() << endl;
    cout << s2.getBottomLeft().display() << endl;
    return 0;
}

In Xcode, I get the expected output of

(2, 1)
(2, 1)

but using clang++, the program fails to compile and throw this error:

test.cpp:38:11: error: expected expression
    Shape s2({1, 2}, {3, 4});
             ^

(This same error is repeated for the {3, 4} thing as well.)

What's going on here?

Answer 1

我需要在调用clang++时指定语言标准。

显然，c++11以上的任何内容都可以。