assertApprox

Assert that two floating point values are approximately equal.

  1. void assertApprox(A value, B target, long ulps, string message, string file, size_t line)
    void
    assertApprox
    (
    A
    B
    )
    (,,
    long ulps = 10
    ,
    string message = "Failed asserting approximately equal"
    ,
    string file = __FILE__
    ,
    size_t line = __LINE__
    )
    if (
    isFloatingPoint!(CommonType!(A, B))
    )
  2. void assertApprox(A value, B target, double epsilon, string message, string file, size_t line)

Parameters

value A

The value used during the assertion.

target B

The target value.

ulps long

The maximum space between two approximately equal floating point numbers measured in units of least precision. A higher number means more approximation.

message string

The error message to display.

file string

The file name where the error occurred. The value is added automatically at the call site.

line size_t

The line where the error occurred. The value is added automatically at the call site.

Throws

DUnitAssertError if the assertation fails.

Examples

float smallestFloatSubnormal = float.min_normal * float.epsilon;
smallestFloatSubnormal.assertApprox(-smallestFloatSubnormal);

double smallestDoubleSubnormal = double.min_normal * double.epsilon;
smallestDoubleSubnormal.assertApprox(-smallestDoubleSubnormal);

0.0f.assertApprox(-0.0f);
(-0.0f).assertApprox(0.0f);
0.0.assertApprox(-0.0);
(-0.0).assertApprox(0.0);
2.0f.assertApprox(1.999999f);
1.999999f.assertApprox(2.0f);
2.0.assertApprox(1.999999999999999);
1.999999999999999.assertApprox(2.0);

// The following tests pass but are open for debate whether or not they should.
float.max.assertApprox(float.infinity);
float.infinity.assertApprox(float.max);
double.infinity.assertApprox(double.max);
double.max.assertApprox(double.infinity);
float.nan.assertApprox(float.nan);
double.nan.assertApprox(double.nan);

// Assert a DUnitAssertError is thrown if assertApprox fails.
10f.assertApprox(0f).assertThrow!(DUnitAssertError)("Failed asserting approximately equal");

See Also

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