Fix block documentation

Author: madsmtm

block2/src/global.rs

@@ -22,6 +22,8 @@ const GLOBAL_DESCRIPTOR: ffi::Block_descriptor_header = ffi::Block_descriptor_he
 ///
 /// If [`ConcreteBlock`] is the [`Fn`]-block equivalent, this is likewise the
 /// [`fn`]-block equivalent.
+///
+/// [`ConcreteBlock`]: crate::ConcreteBlock
 #[repr(C)]
 pub struct GlobalBlock<A, R = ()> {
     layout: ffi::Block_layout,
@@ -105,7 +107,7 @@ where
 /// ```
 /// use block2::global_block;
 /// global_block! {
-///     static ADDER_BLOCK = |x: i32, y: i32,| -> i32 {
+///     static ADDER_BLOCK = |x: i32, y: i32| -> i32 {
 ///         x + y
 ///     }
 /// };
@@ -132,6 +134,8 @@ where
 ///     pub static INVALID_BLOCK = |b: Box<i32>| {}
 /// };
 /// ```
+///
+/// [`Box`]: std::boxed::Box
 #[macro_export]
 macro_rules! global_block {
     // `||` is parsed as one token

block2/src/lib.rs

@@ -43,6 +43,19 @@ It is important to copy your block to the heap (with the `copy` method) before
 passing it to Objective-C; this is because our `ConcreteBlock` is only meant
 to be copied once, and we can enforce this in Rust, but if Objective-C code
 were to copy it twice we could have a double free.
+
+As an optimization if your block doesn't capture any variables, you can use
+the [`global_block!`] macro to create a static block:
+
+```
+use block2::global_block;
+global_block! {
+    static MY_BLOCK = || -> f32 {
+        10.0
+    }
+};
+assert_eq!(unsafe { MY_BLOCK.call(()) }, 10.0);
+```
 */
 
 #![no_std]