Reflection

There are several built-in functions to inspect the code during compile time.
.len on arrays return their length.
$defined(<expr>) returns true if the expression inside is defined.
$alignof(<expr>) returns alignment.
$sizeof(<expr>) returns size.
$checks(<expr>) returns true if the expression inside is valid.
$qnameof(<identifier>) to get the qualified name of the identifier, e.g std::io::printf
$nameof(<identifier>) to get the base name of the identifier, e.g. printf
$typeof(<expr>) returns the type of the expression.
$stringify(<expr>) returns the expression as a string.
<type>.sizeof returns the size of a type.
<type>.alignof returns the alignment of a type.
<type>.nameof return the name of a type.