a delegate used to sink character arrays;
a format specification; Notes: This function is not intended to be used directly, it is used by the format, output or conversion family of functions from Phobos. All standard format options are supported, except digit grouping.
$(PHOBOS format, FormatException, FormatException) if the format specifier is not supported
$(PHOBOS format, FormatSpec, FormatSpec) $(PHOBOS format, format, format) $(PHOBOS conv, to, to) $(PHOBOS stdio, writef, writef) $(PHOBOS stdio, writefln, writefln)
Converts current value to string, passing it to the given sink using the specified format.