glib: Add Value::from_type_unchecked()

This avoids the type checking and panic code generation.

Author: sdroege

glib/src/value.rs

@@ -491,14 +491,30 @@ crate::wrapper! {
 
 impl Value {
     // rustdoc-stripper-ignore-next
-    /// Creates a new `Value` that is initialized with `type_`
-    #[inline]
+    /// Creates a new `Value` that is initialized with `type_`.
+    ///
+    /// # Panics
+    ///
+    /// If `type_` can't be stored in a `Value` this function panics.
     pub fn from_type(type_: Type) -> Self {
         unsafe {
             assert_eq!(
                 gobject_ffi::g_type_check_is_value_type(type_.into_glib()),
                 ffi::GTRUE
             );
+            Self::from_type_unchecked(type_)
+        }
+    }
+
+    // rustdoc-stripper-ignore-next
+    /// Creates a new `Value` that is initialized with `type_`.
+    ///
+    /// # SAFETY
+    ///
+    /// This must be called with a valid `type_` that can be stored in `Value`s.
+    #[inline]
+    pub unsafe fn from_type_unchecked(type_: Type) -> Self {
+        unsafe {
             let mut value = Value::uninitialized();
             gobject_ffi::g_value_init(value.to_glib_none_mut().0, type_.into_glib());
             value
@@ -509,7 +525,7 @@ impl Value {
     /// Creates a new `Value` that is initialized for a given `ValueType`.
     #[inline]
     pub fn for_value_type<T: ValueType>() -> Self {
-        Value::from_type(T::Type::static_type())
+        unsafe { Value::from_type_unchecked(T::Type::static_type()) }
     }
 
     // rustdoc-stripper-ignore-next