Enum

Template housing optimised functions to get the string name of an enum member, or the enum member of a name string.

std.conv.to is typically the go-to for this job; however it quickly bloats the binary and is not performant on larger enums.

@safe

template Enum (

) if (

is(E == enum)

) {

E fromString(string enumstring);

string toString(E value);

}

Members

Functions

fromString E fromString(string enumstring): Takes the member of an enum by string and returns that enum member.
toString string toString(E value): The inverse of fromString, this function takes an enum member value and returns its string identifier.

Parameters

E: enum to base this template on.

Examples

import std.conv : ConvException;
import std.exception  : assertThrown;

{
    enum T
    {
        UNSET,
        QUERY,
        PRIVMSG,
        RPL_ENDOFMOTD
    }

    static assert(Enum!T.fromString("QUERY") == T.QUERY);
    static assert(Enum!T.fromString("PRIVMSG") == T.PRIVMSG);
    static assert(Enum!T.fromString("RPL_ENDOFMOTD") == T.RPL_ENDOFMOTD);
    static assert(Enum!T.fromString("UNSET") == T.UNSET);
    assertThrown!ConvException(Enum!T.fromString("DOESNTEXIST"));  // needs @system

    static assert(Enum!T.toString(T.QUERY) == "QUERY");
    static assert(Enum!T.toString(T.PRIVMSG) == "PRIVMSG");
    static assert(Enum!T.toString(T.RPL_ENDOFMOTD) == "RPL_ENDOFMOTD");
    static assert(Enum!T.toString(cast(T)1234) == "cast(T)1234");
}
{
    enum E
    {
        abc = "abc",
        def = "def",
        ghi = "ghi",
    }

    static assert(Enum!E.fromString("abc") == E.abc);
    static assert(Enum!E.fromString("def") == E.def);
    static assert(Enum!E.fromString("ghi") == E.ghi);
    assertThrown!ConvException(Enum!E.fromString("jkl"));  // as above

    static assert(Enum!E.toString(E.abc) == "abc");
    static assert(Enum!E.toString(E.def) == "def");
    static assert(Enum!E.toString(E.ghi) == "ghi");
    static assert(Enum!E.toString(cast(E)"jkl") == "cast(E)\"jkl\"");
}

lu conv functions

templates

Enum