Two examples that eliminate the need for $bar entirely.

my $foo = 1;
print +($foo)? "True" : "";
[download]

Or, if it's more involved than that...

my $foo = 1;
print do{
    if( $foo ) {
        "True"
    }
}
[download]

In your last example, you asserted that it would be nice if $bar were accessible outside of the if(){} block. But you previously stated that you didn't want to use a global variable (in this case what you really meant was a lexical scoped to package level). The problem is that if $bar is accessible outside of the if(){} block, it's no different from a package-scoped lexical. You don't want your lexicals leaking outside of the block they're defined in; that defeats the purpose of a lexical variable.