print( array{ "a", "b", "c", "D", "e" }.findIndex( @Always ) );
print( array{ "a", "b", "c", "D", "e" }.findIndex( @{ return 0; } ) ); // Never
print( array{ "a", "b", "c", "D", "e" }.findIndex( @( element ) {
  return element == "D";
} ) ); // IfEquals
print( array{ "a", "b", "c", "D", "e" }.findIndex( @IfHighestIndex ) );

print( array{}.findIndex( @DoNotCall ) ); // Returns 0

// Test with a name_arr'd array
var arr := array{ "hello" };
arr.+name := "hello";
print( arr.findIndex( @DoNotCall ) );

// Errors
print( array{}.findIndex() );
print( array{}.findIndex( "foo" ) );

function Always()
  return true;
endfunction

function IfHighestIndex( unused element, index, byref arr )
  return index == arr.size();
endfunction

function DoNotCall()
  exit;
endfunction