Refine inlining.

src/api/custom_syntax.rs

@@ -157,7 +157,6 @@ impl Deref for Expression<'_> {
     type Target = Expr;
 
     #[inline(always)]
-    #[must_use]
     fn deref(&self) -> &Self::Target {
         self.0
     }

src/api/definitions/mod.rs

@@ -77,6 +77,7 @@ pub struct DefinitionsConfig {
 
 impl Default for DefinitionsConfig {
     #[inline(always)]
+    #[must_use]
     fn default() -> Self {
         Self {
             write_headers: false,

src/api/limits.rs

@@ -75,6 +75,7 @@ impl Limits {
 
 impl Default for Limits {
     #[inline(always)]
+    #[must_use]
     fn default() -> Self {
         Self::new()
     }