我读过C++ Primer第五版,书中提到最新的标准支持列表初始化。
我的测试代码如下:
#include <iostream>
#include <string>
#include <cctype>
#include <vector>
using std::cin;
using std::cout;
using std::endl;
using std::string;
using std::vector;
using std::ispunct;
int main(int argc, char *argv[])
{
vector<int> a1 = {0,1,2};
vector<int> a2{0,1,2}; // should be equal to a1
return 0;
}
然后我使用Clang 4.0:
bash-3.2$ c++ --version
Apple clang version 4.0 (tags/Apple/clang-421.0.60) (based on LLVM 3.1svn)
Target: x86_64-apple-darwin12.2.0
Thread model: posix
然后按照以下方式进行编译:
c++ -std=c++11 -Wall playground.cc -o playground
然而,它报错如下:
playground.cc:13:17: error: no matching constructor for initialization of
'vector<int>'
vector<int> a1 = {0,1,2};
^ ~~~~~~~
/usr/include/c++/4.2.1/bits/stl_vector.h:255:9: note: candidate constructor
[with _InputIterator = int] not viable: no known conversion from 'int'
to 'const allocator_type' (aka 'const std::allocator<int>') for 3rd
argument;
vector(_InputIterator __first, _InputIterator __last,
^
/usr/include/c++/4.2.1/bits/stl_vector.h:213:7: note: candidate constructor
not viable: no known conversion from 'int' to 'const allocator_type'
(aka 'const std::allocator<int>') for 3rd argument;
vector(size_type __n, const value_type& __value = value_type(),
我查看了Clang的C++支持状态,看起来它应该已经在Clang 3.1中支持初始化列表。但是为什么我的代码不能正常工作呢?有没有人有关于这个问题的想法?