Sway Reference: Section 9 Annotations inline (FuelLabs#4636)

docs/reference/src/SUMMARY.md

@@ -58,6 +58,7 @@
     - [Storage](./documentation/language/annotations/attributes/storage.md)
     - [Payable](./documentation/language/annotations/attributes/payable.md)
     - [Test](./documentation/language/annotations/attributes/test.md)
+    - [Inline](./documentation/language/annotations/attributes/inline.md)
 - [Traits](./documentation/language/traits/index.md)
 - [Generics](./documentation/language/generics/index.md)
 - [Style Guide](./documentation/language/style-guide/index.md)

docs/reference/src/code/language/annotations/src/main.sw

@@ -65,3 +65,13 @@ fn custom_revert_code() {
     revert(42);
 }
 // ANCHOR_END: revert_code_test
+
+// ANCHOR: never_inline
+#[inline(never)]
+fn foo() {}
+// ANCHOR_END: never_inline
+
+// ANCHOR: always_inline
+#[inline(always)]
+fn bar() {}
+// ANCHOR_END: always_inline

docs/reference/src/documentation/language/annotations/attributes/inline.md

@@ -0,0 +1,21 @@
+# Inline
+
+When making a call the compiler may generate code to call a function where it is defined or it may copy the function code (inline) to prevent additional code generation.
+
+The Sway compiler automatically inlines functions based on internal heuristics; however, the `inline` attribute may be used to suggest, but not require, code generation or code copying.
+
+## Generate code
+
+To suggest code generation use the `never` keyword.
+
+```sway
+{{#include ../../../../code/language/annotations/src/main.sw:never_inline}}
+```
+
+## Copy code
+
+To suggest code copy use the `always` keyword.
+
+```sway
+{{#include ../../../../code/language/annotations/src/main.sw:always_inline}}
+```