没有使用push_back命名类型

Question

i am new to using c++

When I execute the following code

i am aware it shouldn't draw anything at the moment i am just trying to change from using an array for vertex position to using a vector as i want to be able to calculate points then use a push_back to append them.

This minimal example won't compile:

#include <vector>

std::vector<float> vertexPositions;

const float triangle = 0.75f;

vertexPositions.push_back(triangle);

int main(int argc, char** argv)
{
    return 0;
}

I get:

error: ‘vertexPositions’ does not name a type

Answer 1

vertexPositions.push_back(triangle); is a statement. It must be placed inside a function definition. It can not be placed in the global scope like that.

Move that line into for example main , and you should be fine.

Answer 2

是否添加了#include <vector> ？

Answer 3

I see your problem - the following line must appear in your main function :

vertexPositions.push_back(triangle);

I created a console application as an example:

    // test.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <vector>

int _tmain(int argc, _TCHAR* argv[])
{
    std::vector<float> vertexPositions;

    const float triangle = 0.75f;

    vertexPositions.push_back(triangle);
    return 0;
}

Is there something simple you might be missing?