constify and deinline some methods

output/src/op_cond.rs

@@ -2,11 +2,21 @@ use crate::*;
 
 /// Show an item only when a condition is true.
 pub struct When<A>(pub bool, pub A);
-impl<A> When<A> { #[inline] pub fn new (c: bool, a: A) -> Self { Self(c, a) } }
+impl<A> When<A> {
+    /// Create a binary condition.
+    pub const fn new (c: bool, a: A) -> Self {
+        Self(c, a)
+    }
+}
 
 /// Show one item if a condition is true and another if the condition is false
 pub struct Either<A, B>(pub bool, pub A, pub B);
-impl<A, B> Either<A, B> { #[inline] pub fn new (c: bool, a: A, b: B) -> Self { Self(c, a, b) } }
+impl<A, B> Either<A, B> {
+    /// Create a ternary condition.
+    pub const fn new (c: bool, a: A, b: B) -> Self {
+        Self(c, a, b) 
+    }
+}
 
 #[cfg(feature = "dsl")]
 try_from_expr!(<'a, E>: When<RenderBox<'a, E>>: |state, iter| {