var args can't handle void or number literal arguments

[andrewrk]

Issue discovered in #547

Related to #313 #279 #280

Add this test to std/fmt/index.zig:

    {
        var buf1: [32]u8 = undefined;
        const value: void = {};
        const result = bufPrint(buf1[0..], "void: {}\n", value);
        assert(mem.eql(u8, result, "void: {}\n"));
    }

[PavelVozenilek]

When I try this in online compiler:

const std = @import("std");
const warn = std.debug.warn;

pub fn main() void {
  const o  = 1;
  warn("{}\n", o);    
}

I get this error:

/home/runner/.code.tio:6:16: error: compiler bug: integer and float literals in var args function must be casted. https://github.com/zig-lang/zig/issues/557

Something feels wrong here. When the value has explicit type it work.

[bfloch]

Here is another one that points here:

warn("sizeOf u32 {}\n", @sizeOf(u32));

Fixed if the type is explicit:

const u32_size: usize = @sizeOf(u32);
warn("sizeOf u32 {}\n", u32_size);

Or even:

warn("sizeOf u32 {}\n", @intCast(usize, @sizeOf(u32)));

[andrewrk]

Solved by removing var args from the language in a3f6a58. Tuples do not have this limitation.