template value specialization is missing

[MartinNowak]

/// option value types for SocketOption
alias SocketOptionType(SocketOption opt) = int;
/// ditto
alias SocketOptionType(SocketOption opt : SocketOption.linger) = linger;
/// ditto
alias SocketOptionType(SocketOption opt : SocketOption.rcvtimeo) = timeval;
/// ditto
alias SocketOptionType(SocketOption opt : SocketOption.sndtimeo) = timeval;

https://martinnowak.github.io/io/std/io/net/socket/SocketOptionType.html

[MartinNowak]

Fixed, here is the test output.

alias Type(int val) = int;
alias Type(int val : 1) = float;
alias Type(int val : 2 = 2) = double;
alias Type(int val : 3) = byte;