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Using Boost Floating Point Comparison to get bool return value

After going through several articles here and searching, there are many good solutions for comparing floating point numbers.

Such as Boost library: http://www.boost.org/doc/libs/1_34_0/libs/test/doc/components/test_tools/floating_point_comparison.html

I have a Boost library available to me and therefore I want to use it. However, it’s hard for me to get a simple example to show me how to get the boolean return value when comparing two floating point numbers.

For example, they show examples like this: http://www.boost.org/doc/libs/1_50_0/libs/test/doc/html/utf/testing-tools/reference.html

But this does not return a boolean.

Sample psuedo code:

double a = 1.0;
double b = 0.5+0.5;
double percentage = 0.00001; //0.001 %
//Now I want to use the boost library to do something like this:
bool isClose = check_is_close(a, b, percentage);

, bool.

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#include <iostream>
#include <boost/test/floating_point_comparison.hpp>

int main() {
    bool b = boost::test_tools::check_is_close(
        0.01, 0.015, boost::test_tools::percent_tolerance(49.0));
    std::cout << std::boolalpha << b << std::endl; // false

    b = boost::test_tools::check_is_close(
        0.01, 0.015, boost::test_tools::percent_tolerance(51.0));
    std::cout << std::boolalpha << b << std::endl; // true, 51% tolerance is enough to ignore the difference
}

, , :

#include <cmath>
bool is_close(double a, double b, double epsilon = 1e-5) { 
    return std::fabs(a - b) < epsilon; 
}
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/:

inline bool is_close(double a, double b, double tolerance = 1e-5)
{ 
    return (a - b) * (a - b) < tolerance * tolerance;
}

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template <typename Number>
inline boost::test_tools::predicate_result isClose(Number a, Number b, Number tolerance = Number(1e-5))
{
    if ((a-b)*(a-b) < tolerance*tolerance)
    {
        return true;
    }

    boost::test_tools::predicate_result result(false);
    result.message() << a << " != " << b << " within " << tolerance;
    return result;
}
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