numeric_limits::is_exact

Tests if the calculations done on a type are free of rounding errors.

static const bool is_exact = false;

Return Value

true if the calculations are free of rounding errors; false if not.

Remarks

All predefined integer types have exact representations for their values and return false. A fixed-point or rational representation is also considered exact, but a floating-point representation is not.

Example

// numeric_limits_is_exact.cpp
// compile with: /EHsc
#include <iostream>
#include <limits>

using namespace std;

int main( )
{
   cout << "Whether float objects have calculations "
        << "free of rounding errors: "
        << numeric_limits<float>::is_exact
        << endl;
   cout << "Whether double objects have calculations "
        << "free of rounding errors: "
        << numeric_limits<double>::is_exact
        << endl;
   cout << "Whether long int objects have calculations "
        << "free of rounding errors: "
        << numeric_limits<long int>::is_exact
        << endl;
   cout << "Whether unsigned char objects have calculations "
        << "free of rounding errors: "
        << numeric_limits<unsigned char>::is_exact
        << endl;
}

Whether float objects have calculations free of rounding errors: 0
Whether double objects have calculations free of rounding errors: 0
Whether long int objects have calculations free of rounding errors: 1
Whether unsigned char objects have calculations free of rounding errors: 1

Requirements

Header: <limits>

Namespace: std

See Also

Concepts

strstreambuf Class

numeric_limits Members