add *Ex variant of pushFString

Author: natecraddock

src/tests.zig

@@ -259,7 +259,7 @@ test "type of and getting values" {
     );
     lua.pushFunction(ziglua.wrap(add));
     try expectEqualStrings("hello world", lua.pushBytesEx("hello world"));
-    _ = lua.pushFString("%s %s %d", .{ "hello", "world", @as(i32, 10) });
+    lua.pushFString("%s %s %d", .{ "hello", "world", @as(i32, 10) });
     lua.pushValue(1);
 
     // test both typeof and is functions

src/ziglua.zig

@@ -759,10 +759,15 @@ pub const Lua = struct {
         lua.pushClosure(c_fn, 0);
     }
 
+    /// Push a formatted string onto the stack
+    pub fn pushFString(lua: *Lua, fmt: [:0]const u8, args: anytype) void {
+        _ = lua.pushFStringEx(fmt, args);
+    }
+
     /// Push a formatted string onto the stack and return a pointer to the string
-    pub fn pushFString(lua: *Lua, fmt: [:0]const u8, args: anytype) [*]const u8 {
+    pub fn pushFStringEx(lua: *Lua, fmt: [:0]const u8, args: anytype) [*:0]const u8 {
         const ptr = @call(.{}, c.lua_pushfstring, .{ lua.state, fmt } ++ args);
-        return @ptrCast([*]const u8, ptr);
+        return @ptrCast([*:0]const u8, ptr);
     }
 
     /// Pushes the global environment onto the stack