A crate for string formatting using runtime format strings.
This crate provides much the same facilities as std::fmt, with the
additional allowance for format strings which are not known until runtime.
Possible applications include internationalization, scripting, or other
customization.
Each of the standard formatting macros format_args!, format!,
print!, println!, write!, and writeln! have corresponding rt_
variants. Calls which previously succeeded unconditionally now return
Result, which may indicate a bad format string or arguments.
The syntax for format strings and for macro invocations is equivalent to
that used by std::fmt, including support for positional and named
arguments. This crate shells out to the standard library implementations
for as much as possible to ensure feature parity.
This crate makes extensive use of the unstable formatting machinery and therefore requires nightly.