$ perl -c -e'my $x = if (f()) { g(); } else { h(); }'
syntax error at -e line 1, near "= if"
-e had compilation errors.

$ perl -e'my $x = unless (f()) { g(); } else { h(); }'
syntax error at -e line 1, near "= unless"
-e had compilation errors.

##</code><code>##

$ perl -c -e'my $x = ( f() and g() );'
-e syntax OK

$ perl -c -e'my $x = ( if (f()) { g() } );'
syntax error at -e line 1, near "( if"
-e had compilation errors.