Drop load() functions from empty Fn structs (#752)

These functions don't contribute anything and should be removed to clean
up the `features` and `extensions` files, while now also not showing in
the documentation anymore.  The structs remain in place for associated
constants but are replaced with true unit-like structs (no curly
brackets anymore), and unneeded `unsafe impl Send/Sync` are removed as
well.

As these `load()` functions have been removed from the empty
feature-levels on `Entry` and `Device` as well, rather than
instantiating the unit structs and returning those the fields and
`fp_vX_X()` getters have been removed entirely.

Changelog.md

@@ -36,6 +36,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Removed `query_count` parameter from `get_query_pool_results()` in favour of `data.len()` (#644)
 - Removed misnamed, deprecated `debug_utils_set_object_name()` and `debug_utils_set_object_tag()` entirely, use `set_debug_utils_object_name()` and `set_debug_utils_object_tag()` instead (#661)
 - Removed `get_properties` helper from extension wrappers (and `ext::PhysicalDeviceDrm`). Directly call `get_physical_device_properties2()` with a possible chain of multiple structs instead (#728)
+- Removed `fn load()` from empty features and extensions (#752)
+  - Removed empty `entry_fn_1_2`/`entry_fn_1_3` and getters from `Entry`
+  - Removed empty `instance_fn_1_2:` and getters from `Instance`
 
 ## [0.37.2] - 2022-01-11
 

ash/src/device.rs

@@ -40,7 +40,6 @@ impl Device {
 }
 
 /// Vulkan core 1.3
-#[allow(non_camel_case_types)]
 impl Device {
     #[inline]
     pub fn fp_v1_3(&self) -> &vk::DeviceFnV1_3 {
@@ -531,7 +530,6 @@ impl Device {
 }
 
 /// Vulkan core 1.2
-#[allow(non_camel_case_types)]
 impl Device {
     #[inline]
     pub fn fp_v1_2(&self) -> &vk::DeviceFnV1_2 {
@@ -705,7 +703,6 @@ impl Device {
 }
 
 /// Vulkan core 1.1
-#[allow(non_camel_case_types)]
 impl Device {
     #[inline]
     pub fn fp_v1_1(&self) -> &vk::DeviceFnV1_1 {
@@ -952,7 +949,6 @@ impl Device {
 }
 
 /// Vulkan core 1.0
-#[allow(non_camel_case_types)]
 impl Device {
     #[inline]
     pub fn fp_v1_0(&self) -> &vk::DeviceFnV1_0 {

ash/src/entry.rs

@@ -21,14 +21,11 @@ pub struct Entry {
     static_fn: vk::StaticFn,
     entry_fn_1_0: vk::EntryFnV1_0,
     entry_fn_1_1: vk::EntryFnV1_1,
-    entry_fn_1_2: vk::EntryFnV1_2,
-    entry_fn_1_3: vk::EntryFnV1_3,
     #[cfg(feature = "loaded")]
     _lib_guard: Option<Arc<Library>>,
 }
 
 /// Vulkan core 1.0
-#[allow(non_camel_case_types)]
 impl Entry {
     /// Load default Vulkan library for the current platform
     ///
@@ -151,15 +148,11 @@ impl Entry {
         };
         let entry_fn_1_0 = vk::EntryFnV1_0::load(load_fn);
         let entry_fn_1_1 = vk::EntryFnV1_1::load(load_fn);
-        let entry_fn_1_2 = vk::EntryFnV1_2::load(load_fn);
-        let entry_fn_1_3 = vk::EntryFnV1_3::load(load_fn);
 
         Self {
             static_fn,
             entry_fn_1_0,
             entry_fn_1_1,
-            entry_fn_1_2,
-            entry_fn_1_3,
             #[cfg(feature = "loaded")]
             _lib_guard: None,
         }
@@ -273,7 +266,6 @@ impl Entry {
 }
 
 /// Vulkan core 1.1
-#[allow(non_camel_case_types)]
 impl Entry {
     #[inline]
     pub fn fp_v1_1(&self) -> &vk::EntryFnV1_1 {
@@ -294,24 +286,6 @@ impl Entry {
     }
 }
 
-/// Vulkan core 1.2
-#[allow(non_camel_case_types)]
-impl Entry {
-    #[inline]
-    pub fn fp_v1_2(&self) -> &vk::EntryFnV1_2 {
-        &self.entry_fn_1_2
-    }
-}
-
-/// Vulkan core 1.3
-#[allow(non_camel_case_types)]
-impl Entry {
-    #[inline]
-    pub fn fp_v1_3(&self) -> &vk::EntryFnV1_3 {
-        &self.entry_fn_1_3
-    }
-}
-
 #[cfg(feature = "linked")]
 #[cfg_attr(docsrs, doc(cfg(feature = "linked")))]
 impl Default for Entry {

ash/src/instance.rs

@@ -13,7 +13,6 @@ pub struct Instance {
 
     pub(crate) instance_fn_1_0: vk::InstanceFnV1_0,
     pub(crate) instance_fn_1_1: vk::InstanceFnV1_1,
-    pub(crate) instance_fn_1_2: vk::InstanceFnV1_2,
     pub(crate) instance_fn_1_3: vk::InstanceFnV1_3,
 }
 
@@ -28,7 +27,6 @@ impl Instance {
 
             instance_fn_1_0: vk::InstanceFnV1_0::load(load_fn),
             instance_fn_1_1: vk::InstanceFnV1_1::load(load_fn),
-            instance_fn_1_2: vk::InstanceFnV1_2::load(load_fn),
             instance_fn_1_3: vk::InstanceFnV1_3::load(load_fn),
         }
     }
@@ -40,7 +38,6 @@ impl Instance {
 }
 
 /// Vulkan core 1.3
-#[allow(non_camel_case_types)]
 impl Instance {
     #[inline]
     pub fn fp_v1_3(&self) -> &vk::InstanceFnV1_3 {
@@ -84,17 +81,7 @@ impl Instance {
     }
 }
 
-/// Vulkan core 1.2
-#[allow(non_camel_case_types)]
-impl Instance {
-    #[inline]
-    pub fn fp_v1_2(&self) -> &vk::InstanceFnV1_2 {
-        &self.instance_fn_1_2
-    }
-}
-
 /// Vulkan core 1.1
-#[allow(non_camel_case_types)]
 impl Instance {
     #[inline]
     pub fn fp_v1_1(&self) -> &vk::InstanceFnV1_1 {
@@ -325,7 +312,6 @@ impl Instance {
 }
 
 /// Vulkan core 1.0
-#[allow(non_camel_case_types)]
 impl Instance {
     #[inline]
     pub fn fp_v1_0(&self) -> &vk::InstanceFnV1_0 {

ash/src/vk/features.rs

@@ -4296,29 +4296,9 @@ impl DeviceFnV1_1 {
     }
 }
 #[derive(Clone)]
-pub struct EntryFnV1_2 {}
-unsafe impl Send for EntryFnV1_2 {}
-unsafe impl Sync for EntryFnV1_2 {}
-impl EntryFnV1_2 {
-    pub fn load<F>(mut _f: F) -> Self
-    where
-        F: FnMut(&::std::ffi::CStr) -> *const c_void,
-    {
-        Self {}
-    }
-}
+pub struct EntryFnV1_2;
 #[derive(Clone)]
-pub struct InstanceFnV1_2 {}
-unsafe impl Send for InstanceFnV1_2 {}
-unsafe impl Sync for InstanceFnV1_2 {}
-impl InstanceFnV1_2 {
-    pub fn load<F>(mut _f: F) -> Self
-    where
-        F: FnMut(&::std::ffi::CStr) -> *const c_void,
-    {
-        Self {}
-    }
-}
+pub struct InstanceFnV1_2;
 #[derive(Clone)]
 pub struct DeviceFnV1_2 {
     pub cmd_draw_indirect_count: crate::vk::PFN_vkCmdDrawIndirectCount,
@@ -4595,17 +4575,7 @@ impl DeviceFnV1_2 {
     }
 }
 #[derive(Clone)]
-pub struct EntryFnV1_3 {}
-unsafe impl Send for EntryFnV1_3 {}
-unsafe impl Sync for EntryFnV1_3 {}
-impl EntryFnV1_3 {
-    pub fn load<F>(mut _f: F) -> Self
-    where
-        F: FnMut(&::std::ffi::CStr) -> *const c_void,
-    {
-        Self {}
-    }
-}
+pub struct EntryFnV1_3;
 #[derive(Clone)]
 pub struct InstanceFnV1_3 {
     pub get_physical_device_tool_properties: crate::vk::PFN_vkGetPhysicalDeviceToolProperties,

generator/src/lib.rs

@@ -22,6 +22,7 @@ use std::{
     borrow::Cow,
     collections::{BTreeMap, HashMap, HashSet},
     fmt::Display,
+    ops::Not,
     path::Path,
 };
 use syn::Ident;
@@ -1032,34 +1033,48 @@ fn generate_function_pointers<'a>(
             .to_tokens(tokens)
         }
     }
+    let loaders = commands.iter().map(CommandToLoader);
+
+    let loader = commands.is_empty().not().then(|| {
+        quote! {
+            impl #ident {
+                pub fn load<F>(mut _f: F) -> Self
+                    where F: FnMut(&::std::ffi::CStr) -> *const c_void
+                {
+                    Self {
+                        #(#loaders,)*
+                    }
+                }
+            }
+        }
+    });
 
     let pfn_typedefs = commands
         .iter()
         .filter(|pfn| pfn.type_needs_defining)
         .map(CommandToType);
     let members = commands.iter().map(CommandToMember);
-    let loaders = commands.iter().map(CommandToLoader);
+
+    let struct_contents = if commands.is_empty() {
+        quote! { pub struct #ident; }
+    } else {
+        quote! {
+            pub struct #ident {
+                #(#members,)*
+            }
+
+            unsafe impl Send for #ident {}
+            unsafe impl Sync for #ident {}
+        }
+    };
 
     quote! {
         #(#pfn_typedefs)*
 
         #[derive(Clone)]
-        pub struct #ident {
-            #(#members,)*
-        }
+        #struct_contents
 
-        unsafe impl Send for #ident {}
-        unsafe impl Sync for #ident {}
-
-        impl #ident {
-            pub fn load<F>(mut _f: F) -> Self
-                where F: FnMut(&::std::ffi::CStr) -> *const c_void
-            {
-                Self {
-                    #(#loaders,)*
-                }
-            }
-        }
+        #loader
     }
 }
 pub struct ExtensionConstant<'a> {