Compiler Error C3027

  • Article

'clause' : arithmetic or pointer expression expected

A clause that requires an arithmetic or pointer expression was passed another kind of expression.

Example

The following sample generates C3027:

// C3027.cpp
// compile with: /openmp /link vcomps.lib
#include <stdio.h>
#include "omp.h"

struct MyStruct 
{
    int x;
} m_MyStruct;

int main() 
{
    int i;

    puts("Test with class MyStruct:\n");
    #pragma omp parallel for if(m_MyStruct)   // C3027
    for (i = 1; i <= 2; ++i)
        printf_s("Hello World - thread %d - iteration %d\n",
                 omp_get_thread_num(), i);

    puts("Test with int:\n");
    #pragma omp parallel for if(9)   // OK
    for (i = 1; i <= 2; ++i)
        printf_s("Hello World - thread %d - iteration %d\n",
                 omp_get_thread_num(), i);
}