defs.zig

const std = @import("std");
const mem = std.mem;

const X: usize = 100;

fn isConstDefined(name: []const u8) bool {
    const type_info = @typeInfo(@This());
    inline for (type_info.Struct.defs) |def| {
        if (mem.eql(u8, def.name, name)) {
            return true;
        }
    }
    return false;
}

test "defs" {
    std.debug.warn("\nIs X defined? {}\n", isConstDefined("X"));
    std.debug.warn("\nIs Y defined? {}\n", isConstDefined("Y"));
}