trace_macros::connect_args!

macro_rules! connect_args {
    (formatter=>$fr:expr, sep=>$sep:expr, $($arg:expr),+) => { ... };
    (sep=>$sep:expr, $($arg:expr),+) => { ... };
    (formatter=>$fr:expr, $($arg:expr),+) => { ... };
    ($msg:expr) => { ... };
    ($($arg:expr),+) => { ... };
}

Macro to concat several arguments into one string.

Arguments:

• sep is a string which is used to separate arguments. Default is white-space.
• formatter is a valid string to pass in format! . Default is "{}".

Usage:

• connect_args!(formatter=>[String], sep=>[String], [arg1, arg2, ..., argN])
• connect_args!(sep=>[String], [arg1, arg2, ..., argN])
• connect_args!(formatter=>[String], [arg1, arg2, ..., argN])
• connect_args!([arg1, arg2, ..., argN])