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// lesson 2: numbers
//
// a digit is a syntax error. the only number literal is ::difference<'a', 'b'>,
// the distance between two characters. 'F' - 'A' is 5. ::emit takes a type, and a
// value is not a type, so wrap it in ::decltype(...) to make it one
::emit<::decltype(::difference<'F', 'A'>)>::commit;
// arithmetic is ::sum, ::product and ::quotient.
// no operators
// no precedence
// no problem
::emit<
::decltype(
::sum<
::difference<'F', 'A'>,
::difference<'C', 'A'>
>
)
>::commit;
::emit<
::decltype(
::product<
::difference<'D', 'A'>,
::difference<'E', 'A'>
>
)
>::commit;
::emit<
::decltype(
::quotient<
::difference<'H', 'A'>,
::difference<'C', 'A'>
>
)
>::commit;
// ::integral_constant<::size_t, V>::value is V. it exists so you can write more
// ::extent<T>::value is the length of an array type, and 0 for anything else
// this is the long way to write 20
::emit<
::decltype(
::extent<
::array<
::byte,
::integral_constant<
::size_t,
::difference<'Z', 'F'>
>::value
>
>::value
)
>::commit;
// emitting a type that is not a value prints the name of the type
::emit<::remove_cv_t<::int32_t>>::commit;
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