c++ vector initialization

问题:

I have been using the following vector initialization with values in Code::Blocks and MingW compiler:

vector<int> v0 {1,2,3,4};

After that I had to move the code to a visual studio project (c++) and I tried to build. I got the following error:
local function definitions are illegal

Visual Studio compiler does not support this kind of initialization?
How do I need to change the code to make it compatible?
I want to initialize vector and fill it with values at the same time, just like an array.

回答1:

Visual C++ does not yet support initializer lists.

The closest you can get to this syntax is to use an array to hold the initializer then use the range constructor:

std::array<int, 4> v0_init = { 1, 2, 3, 4 };
std::vector<int> v0(v0_init.begin(), v0_init.end());

回答2:

You can do nearly that in VS2013

vector<int> v0{ { 1, 2, 3, 4 } };

Full example

#include <vector>
#include <iostream>
int main()
{    
    using namespace std;
    vector<int> v0{ { 1, 2, 3, 4 } };
    for (auto& v : v0){
        cout << " " << v;
    }
    cout << endl;
    return 0;
}

回答3:

Another alternative is boost::assign:

#include <boost/assign.hpp>


using namespace boost::assign;
vector<int> v;
v += 1,2,3,4;

回答4:

I have defined a macro :

#define init_vector(type, name, ...)\
    const type _init_vector_##name[] { __VA_ARGS__ };\
    vector<type> name(_init_vector_##name, _init_vector_##name + _countof(_init_vector_##name))

and use like this :

init_vector(string, spell, "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine" );

for(auto &a : spell)
  std::cout<< a <<" ";

回答5:

If you're using Visual Studio 2015, the way to initialize a vector using a list is:

vector<int> v = {3, (1,2,3)};

So, the first parameter (3) specifies size and the list is the second parameter.