[expr.prim.general] Use code font for ~.

Author: zygoloid

source/expressions.tex

@@ -491,10 +491,10 @@
 point in its potential scope~(\ref{basic.scope.class}).
 \exitnote 
 Where
-\grammarterm{class-name} \tcode{::\tilde} \grammarterm{class-name} is used,
+\grammarterm{class-name} \tcode{::\tilde}~\grammarterm{class-name} is used,
 the two \grammarterm{class-name}{s} shall refer to the same class; this
 notation names the destructor~(\ref{class.dtor}).
-The form \grammarterm{\tilde} \grammarterm{decltype-specifier} also denotes the destructor,
+The form \tcode{\tilde}~\grammarterm{decltype-specifier} also denotes the destructor,
 but it shall not be used as the \grammarterm{unqualified-id} in a \grammarterm{qualified-id}.
 \enternote 
 a \grammarterm{typedef-name} that names a class is a