Compiler Error C3037

'var' : variable in 'reduction' clause must be shared in enclosing context

A variable specified in a reduction clause may not be private to each thread in the context.

The following sample generates C3037:

// C3037.cpp
// compile with: /openmp /c
int g_i;

int main() {
   int i;

   #pragma omp parallel private(g_i)
   // try the following line instead
   // #pragma omp parallel
   {
      #pragma omp for reduction(+:g_i)   // C3037
      for (i = 0 ; i < 10 ; ++i) {
         g_i += i;
      }
   }
}