c++ - 如何解释C++字符串中的\u转义代码？

Question

我想以编程方式在C++中构建Unicode字形的列表，但是我找不到解决编译器错误\u used with no following hex digits的方法

#include <iostream>
#include <sstream>

using namespace std;

int main() 
{
    int unicode = 0x2200;
    stringstream result;
    for (int i = 0; i<0x0F; ++i)
    {
    unicode += i ;
    result << "\u" << hex << unicode << "\n";
    };

    cout << result.str();

    return 0;
}```

Answer 1

用于指示通用字符名称。从this源中，我们可以看到更详细的描述:

In character literals and native (non-raw) string literals, any character may be represented by a universal character name. Universal character names are formed by a prefix \U followed by an eight-digit Unicode code point, or by a prefix \u followed by a four digit Unicode code point. All eight or four digits, respectively, must be present to make a well-formed universal character name.

您得到的错误很可能是由于缺少变量值。我看不到在提供的上下文中 hex的声明位置。