C++ Insights

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// Type your code here, or load an example.
//double fma(double, double, double);
//float fma(float, float, float);
#include <cmath>
#include <assert.h>
void test(){
    float f = 1.0f / 3.0f;
    double d = f;
    int i = 0;
    auto Check = [&](bool Cond) { assert(Cond); };
    // f * f + 3.0f will be different if promoted to double.
    float floatResult = fma(f, f, 3.0f);
    double doubleResult = fma(d, d, 3.0);
    Check(floatResult != doubleResult);

// check promote to float.
    Check(fma(f, f, 3) == floatResult);
    Check(fma(f, f, (char)3) == floatResult);
    Check(fma(f, f, (unsigned char)3) == floatResult);
    Check(fma(f, f, (short)3) == floatResult);
    Check(fma(f, f, (unsigned short)3) == floatResult);
    Check(fma(f, f, (int)3) == floatResult);
    Check(fma(f, f, (unsigned int)3) == floatResult);
    Check(fma(f, f, (long)3) == floatResult);
    Check(fma(f, f, (unsigned long)3) == floatResult);
    Check(fma(f, f, true) == fma(f, f, 1.0f));

// check promote to double.
    Check(fma(d, (double)f, 3) == doubleResult);
    Check(fma(d, (double)f, (char)3) == doubleResult);
    Check(fma(d, (double)f, (unsigned char)3) == doubleResult);
    Check(fma(d, (double)f, (short)3) == doubleResult);
    Check(fma(d, (double)f, (unsigned short)3) == doubleResult);
    Check(fma(d, (double)f, (int)3) == doubleResult);
    Check(fma(d, (double)f, (unsigned int)3) == doubleResult);
    Check(fma(d, (double)f, (long)3) == doubleResult);
    Check(fma(d, (double)f, (unsigned long)3) == doubleResult);
    Check(fma(d, (double)f, true) == fma((double)f, (double)f, 1.0));
  
}

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