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Precision specifier for non-number arguments #90
Description
From the docs:
The precision is a decimal number indicating how many digits should be displayed after the decimal point for a floating-point value formatted with 'f' and 'F', or before and after the decimal point for a floating-point value formatted with 'g' or 'G'. For non-number types the field indicates the maximum field size - in other words, how many characters will be used from the field content. The precision is not allowed for integer values.
So I tried to use precision on a string argument, for example:
std::cout << fmt::format("{0:.2s}", "test") << std::endl;
which results in segfault:
terminate called after throwing an instance of 'fmt::FormatError'
what(): precision specifier requires floating-point argument
Aborted (core dumped)
Also note that printf allows the precision specifier even for integer arguments:
Precision specifies the minimum number of digits to appear.
Activity
vitaut commentedon Jan 7, 2015
Good catch, I'll have a look into this. Thanks!
vitaut commentedon Jan 8, 2015
Fixed in 43aebf5. As for "precision" for integer arguments, the
fmt::formatfunction follows Python's conventions in not allowing it, but as in Python you can use a combination of fill and width for similar effect:or use
fmt::sprintfwhich followsprintfconventions and allows precision for integer arguments.lahwaacz commentedon Jan 11, 2015
Thanks, I was not aware of Python's approach so in that case everything is all right...