If a double is demoted to a float or a long double is demoted to a double or a float, and the initial value exceeds the maximum of the demoted type, then the value of the result undefined.
Non-Compliant Code Example
This non-compliant code illustrates possible undefined behavior associated with demoting floating point represented numbers.
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In the assignments above, it is possible that the variable d1 exceeds the maximum value that can be stored by a float or that the variable ld exceeds the maximum value that can be represented as either a float or a double.
Compliant Code Example
This compliant code properly checks to see whether the values to be stored are too large to be represented.
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