bun.sh/src/meta.zig

const std = @import("std");

pub usingnamespace std.meta;

pub fn ReturnOf(comptime function: anytype) type {
    return ReturnOfType(@TypeOf(function));
}

pub fn ReturnOfType(comptime Type: type) type {
    const typeinfo: std.builtin.Type.Fn = @typeInfo(Type);
    return typeinfo.return_type orelse void;
}

// partially emulates behaviour of @typeName in previous Zig versions,
// converting "some.namespace.MyType" to "MyType"
pub fn typeBaseName(comptime fullname: []const u8) []const u8 {

    // leave type name like "namespace.WrapperType(namespace.MyType)" as it is
    const baseidx = comptime std.mem.indexOf(u8, fullname, "(");
    if (baseidx != null) return fullname;

    const idx = comptime std.mem.lastIndexOf(u8, fullname, ".");

    const name = if (idx == null) fullname else fullname[(idx.? + 1)..];
    return comptime std.fmt.comptimePrint("{s}", .{name});
}