glfw: add Window.hintString

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>

glfw/src/Window.zig

@@ -47,6 +47,34 @@ pub fn hint(hint_const: usize, value: isize) Error!void {
     try getError();
 }
 
+/// Sets the specified window hint to the desired value.
+///
+/// This function sets hints for the next call to glfw.Window.create. The hints, once set, retain
+/// their values until changed by a call to this function or glfw.Window.defaultHints, or until the
+/// library is terminated.
+///
+/// Only string type hints can be set with this function. Integer value hints are set with
+/// glfw.Window.hint.
+///
+/// This function does not check whether the specified hint values are valid. If you set hints to
+/// invalid values this will instead be reported by the next call to glfw.window.create.
+///
+/// Some hints are platform specific. These may be set on any platform but they will only affect
+/// their specific platform. Other platforms will ignore them. Setting these hints requires no
+/// platform specific headers or functions.
+///
+/// Possible errors include glfw.Error.NotInitialized and glfw.Error.InvalidEnum.
+///
+/// @pointer_lifetime The specified string is copied before this function returns.
+///
+/// @thread_safety This function must only be called from the main thread.
+///
+/// see also: window_hints, glfw.Window.hint, glfw.Window.defaultHints
+pub fn hintString(hint_const: usize, value: [:0]const u8) Error!void {
+    c.glfwWindowHintString(@intCast(c_int, hint_const), &value[0]);
+    try getError();
+}
+
 test "defaultHints" {
     const glfw = @import("main.zig");
     try glfw.init();
@@ -63,3 +91,11 @@ test "hint" {
     try hint(glfw.focused, 1);
     try defaultHints();
 }
+
+test "hintString" {
+    const glfw = @import("main.zig");
+    try glfw.init();
+    defer glfw.terminate();
+
+    try hintString(glfw.x11_class_name, "myclass");
+}