Typographic fixes, spacing after \opt

* occurrences of "\opt \terminal{" apparently always require "\opt{}" to not eat
  the intervening space (despite the \xspace in the definition of \opt)

* cleaned up two occurrences of "\opt\ " (in

    noptr-abstract-pack-declarator \terminal{[} constant-expression\opt\ \terminal{]} attribute-specifier-seq\opt\br

  in declarators.tex and grammar.tex) to consistenly use "\opt{}" instead

* cleaned up two occurrences of "\opt{}" (in

    pp-tokens\opt{} new-line

  in grammar.tex and preprocessor.tex) that did not need the "{}"

Author: stbergmann

source/classes.tex

@@ -30,7 +30,7 @@
 
 \begin{bnf}
 \nontermdef{class-specifier}\br
-    class-head \terminal{\{} member-specification\opt \terminal{\}}
+    class-head \terminal{\{} member-specification\opt{} \terminal{\}}
 \end{bnf}
 
 \begin{bnf}
@@ -449,7 +449,7 @@
 
 \begin{bnf}
 \nontermdef{member-declaration}\br
-    attribute-specifier-seq\opt decl-specifier-seq\opt member-declarator-list\opt \terminal{;}\br
+    attribute-specifier-seq\opt decl-specifier-seq\opt member-declarator-list\opt{} \terminal{;}\br
     function-definition\br
     using-declaration\br
     static_assert-declaration\br
@@ -468,7 +468,7 @@
 \nontermdef{member-declarator}\br
     declarator virt-specifier-seq\opt pure-specifier\opt\br
     declarator brace-or-equal-initializer\opt\br
-    identifier\opt attribute-specifier-seq\opt \terminal{:} constant-expression
+    identifier\opt attribute-specifier-seq\opt{} \terminal{:} constant-expression
 \end{bnf}
 
 \begin{bnf}
@@ -1390,7 +1390,7 @@
 A \grammarterm{member-declarator} of the form
 
 \begin{ncbnftab}
-identifier\opt  attribute-specifier-seq\opt \terminal{:} constant-expression
+identifier\opt  attribute-specifier-seq\opt{} \terminal{:} constant-expression
 \end{ncbnftab}
 
 \indextext{\idxcode{:}!field declaration}%

source/declarations.tex

@@ -44,12 +44,12 @@
 
 \begin{bnf}
 \nontermdef{alias-declaration}\br
-    \terminal{using} identifier attribute-specifier-seq\opt \terminal{=} type-id \terminal{;}
+    \terminal{using} identifier attribute-specifier-seq\opt{} \terminal{=} type-id \terminal{;}
 \end{bnf}
 
 \begin{bnf}
 \nontermdef{simple-declaration}\br
-    decl-specifier-seq\opt init-declarator-list\opt \terminal{;}\br
+    decl-specifier-seq\opt init-declarator-list\opt{} \terminal{;}\br
     attribute-specifier-seq decl-specifier-seq\opt init-declarator-list \terminal{;}
 \end{bnf}
 
@@ -84,7 +84,7 @@
 \grammarterm{simple-declaration}
 
 \begin{ncsimplebnf}
-attribute-specifier-seq\opt decl-specifier-seq\opt init-declarator-list\opt \terminal{;}
+attribute-specifier-seq\opt decl-specifier-seq\opt init-declarator-list\opt{} \terminal{;}
 \end{ncsimplebnf}
 
 is divided into three parts.
@@ -1778,7 +1778,7 @@
 
 \begin{bnf}
 \nontermdef{enum-specifier}\br
-    enum-head \terminal{\{} enumerator-list\opt \terminal{\}}\br
+    enum-head \terminal{\{} enumerator-list\opt{} \terminal{\}}\br
     enum-head \terminal{\{} enumerator-list \terminal{, \}}
 \end{bnf}
 
@@ -1791,7 +1791,7 @@
 
 \begin{bnf}
 \nontermdef{opaque-enum-declaration}\br
-    enum-key attribute-specifier-seq\opt identifier enum-base\opt \terminal{;}
+    enum-key attribute-specifier-seq\opt identifier enum-base\opt{} \terminal{;}
 \end{bnf}
 
 \begin{bnf}
@@ -2130,7 +2130,7 @@
 
 \begin{bnf}
 \nontermdef{unnamed-namespace-definition}\br
-        \terminal{inline\opt} \terminal{namespace} attribute-specifier-seq\opt \terminal{\{} namespace-body \terminal{\}}
+        \terminal{inline\opt} \terminal{namespace} attribute-specifier-seq\opt{} \terminal{\{} namespace-body \terminal{\}}
 \end{bnf}
 
 \begin{bnf}
@@ -2283,7 +2283,7 @@
 replaced by
 
 \begin{ncsimplebnf}
-\terminal{inline}\opt \terminal{namespace} \uniquens{} \terminal{\{ /* empty body */ \}}\br
+\terminal{inline}\opt{} \terminal{namespace} \uniquens{} \terminal{\{ /* empty body */ \}}\br
 \terminal{using namespace} \uniquens{} \terminal{;}\br
 \terminal{namespace} \uniquens{} \terminal{\{} namespace-body \terminal{\}}
 \end{ncsimplebnf}
@@ -2908,7 +2908,7 @@
 
 \begin{bnf}
 \nontermdef{using-directive}\br
-    attribute-specifier-seq\opt \terminal{using  namespace} nested-name-specifier\opt namespace-name \terminal{;}
+    attribute-specifier-seq\opt{} \terminal{using  namespace} nested-name-specifier\opt namespace-name \terminal{;}
 \end{bnf}
 
 \pnum
@@ -3161,7 +3161,7 @@
 %
 \begin{bnf}
 \nontermdef{linkage-specification}\br
-    \terminal{extern} string-literal \terminal{\{} declaration-seq\opt \terminal{\}}\br
+    \terminal{extern} string-literal \terminal{\{} declaration-seq\opt{} \terminal{\}}\br
     \terminal{extern} string-literal declaration
 \end{bnf}
 
@@ -3403,8 +3403,8 @@
 
 \begin{bnf}
 \nontermdef{alignment-specifier}\br
-  \terminal{alignas (} type-id \terminal{...}\opt \terminal{)}\br
-  \terminal{alignas (} constant-expression \terminal{...}\opt \terminal{)}
+  \terminal{alignas (} type-id \terminal{...}\opt{} \terminal{)}\br
+  \terminal{alignas (} constant-expression \terminal{...}\opt{} \terminal{)}
 \end{bnf}
 
 \begin{bnf}

source/declarators.tex

@@ -121,7 +121,7 @@
 \nontermdef{noptr-declarator}\br
     declarator-id attribute-specifier-seq\opt\br
     noptr-declarator parameters-and-qualifiers\br
-    noptr-declarator \terminal{[} constant-expression\opt \terminal{]} attribute-specifier-seq\opt\br
+    noptr-declarator \terminal{[} constant-expression\opt{} \terminal{]} attribute-specifier-seq\opt\br
     \terminal{(} ptr-declarator \terminal{)}
 \end{bnf}
 
@@ -218,7 +218,7 @@
 \begin{bnf}
 \nontermdef{noptr-abstract-declarator}\br
     noptr-abstract-declarator\opt parameters-and-qualifiers\br
-    noptr-abstract-declarator\opt \terminal{[} constant-expression\opt{} \terminal{]} attribute-specifier-seq\opt\br
+    noptr-abstract-declarator\opt{} \terminal{[} constant-expression\opt{} \terminal{]} attribute-specifier-seq\opt\br
     \terminal{(} ptr-abstract-declarator \terminal{)}
 \end{bnf}
 
@@ -231,7 +231,7 @@
 \begin{bnf}
 \nontermdef{noptr-abstract-pack-declarator}\br
     noptr-abstract-pack-declarator parameters-and-qualifiers\br
-    noptr-abstract-pack-declarator \terminal{[} constant-expression\opt\ \terminal{]} attribute-specifier-seq\opt\br
+    noptr-abstract-pack-declarator \terminal{[} constant-expression\opt{} \terminal{]} attribute-specifier-seq\opt\br
     \terminal{...}
 \end{bnf}
 
@@ -583,7 +583,7 @@
 has the form
 
 \begin{ncsimplebnf}
-\terminal{*} attribute-specifier-seq\opt cv-qualifier-seq\opt \terminal{D1}
+\terminal{*} attribute-specifier-seq\opt cv-qualifier-seq\opt{} \terminal{D1}
 \end{ncsimplebnf}
 
 and the type of the identifier in the declaration
@@ -697,8 +697,8 @@
 has either of the forms
 
 \begin{ncsimplebnf}
-\terminal{\&} attribute-specifier-seq\opt \terminal{D1}\br
-\terminal{\&\&} attribute-specifier-seq\opt \terminal{D1}
+\terminal{\&} attribute-specifier-seq\opt{} \terminal{D1}\br
+\terminal{\&\&} attribute-specifier-seq\opt{} \terminal{D1}
 \end{ncsimplebnf}
 
 and the type of the identifier in the declaration
@@ -1003,7 +1003,7 @@
 has the form
 
 \begin{ncsimplebnf}
-\terminal{D1 [} constant-expression\opt \terminal{]} attribute-specifier-seq\opt
+\terminal{D1 [} constant-expression\opt{} \terminal{]} attribute-specifier-seq\opt
 \end{ncsimplebnf}
 
 and the type of the identifier in the declaration
@@ -1357,7 +1357,7 @@
 \indextext{declaration!function}%
 \begin{bnf}
 \nontermdef{parameter-declaration-clause}\br
-parameter-declaration-list\opt \terminal{...}\opt\br
+parameter-declaration-list\opt{} \terminal{...}\opt\br
     parameter-declaration-list \terminal{, ...}
 \end{bnf}
 
@@ -1372,7 +1372,7 @@
     attribute-specifier-seq\opt decl-specifier-seq declarator\br
     attribute-specifier-seq\opt decl-specifier-seq declarator \terminal{=} initializer-clause\br
     attribute-specifier-seq\opt decl-specifier-seq abstract-declarator\opt\br
-    attribute-specifier-seq\opt decl-specifier-seq abstract-declarator\opt \terminal{=} initializer-clause
+    attribute-specifier-seq\opt decl-specifier-seq abstract-declarator\opt{} \terminal{=} initializer-clause
 \end{bnf}
 
 The optional \grammarterm{attribute-specifier-seq} in a \grammarterm{parameter-declaration}
@@ -2182,7 +2182,7 @@
 A function definition of the form:
 
 \begin{ncbnf}
-    attribute-specifier-seq\opt decl-specifier-seq\opt declarator virt-specifier-seq\opt \terminal{ = default ;}
+    attribute-specifier-seq\opt decl-specifier-seq\opt declarator virt-specifier-seq\opt{} \terminal{ = default ;}
 \end{ncbnf}
 
 is called an \grammarterm{explicitly-defaulted} definition.
@@ -2284,7 +2284,7 @@
 A function definition of the form:
 
 \begin{ncbnf}
-    attribute-specifier-seq\opt decl-specifier-seq\opt declarator virt-specifier-seq\opt \terminal{ = delete ;}
+    attribute-specifier-seq\opt decl-specifier-seq\opt declarator virt-specifier-seq\opt{} \terminal{ = delete ;}
 \end{ncbnf}
 
 is called a \term{deleted definition}. A function with a

source/derived.tex

@@ -31,7 +31,7 @@
 \begin{bnf}
 \nontermdef{base-specifier}\br
     attribute-specifier-seq\opt base-type-specifier\br
-    attribute-specifier-seq\opt \terminal{virtual} access-specifier\opt base-type-specifier\br
+    attribute-specifier-seq\opt{} \terminal{virtual} access-specifier\opt base-type-specifier\br
     attribute-specifier-seq\opt access-specifier \terminal{virtual}\opt base-type-specifier
 \end{bnf}
 

source/exceptions.tex

@@ -700,7 +700,7 @@
 
 \begin{bnf}
 \nontermdef{dynamic-exception-specification}\br
-    \terminal{throw (} type-id-list\opt \terminal{)}
+    \terminal{throw (} type-id-list\opt{} \terminal{)}
 \end{bnf}
 
 \begin{bnf}

source/expressions.tex

@@ -583,7 +583,7 @@
 
 \begin{bnf}
 \nontermdef{lambda-introducer}\br
-    \terminal{[} lambda-capture\opt \terminal{]}
+    \terminal{[} lambda-capture\opt{} \terminal{]}
 \end{bnf}
 
 \begin{bnf}
@@ -1249,9 +1249,9 @@
     primary-expression\br
     postfix-expression \terminal{[} expression \terminal{]}\br
     postfix-expression \terminal{[} braced-init-list \terminal{]}\br
-    postfix-expression \terminal{(} expression-list\opt \terminal{)}\br
-    simple-type-specifier \terminal{(} expression-list\opt \terminal{)}\br
-    typename-specifier \terminal{(} expression-list\opt \terminal{)}\br
+    postfix-expression \terminal{(} expression-list\opt{} \terminal{)}\br
+    simple-type-specifier \terminal{(} expression-list\opt{} \terminal{)}\br
+    typename-specifier \terminal{(} expression-list\opt{} \terminal{)}\br
     simple-type-specifier braced-init-list\br
     typename-specifier braced-init-list\br
     postfix-expression \terminal{. template}\opt id-expression\br
@@ -2816,8 +2816,8 @@
 
 \begin{bnf}
 \nontermdef{new-expression}\br
-    \terminal{::}\opt \terminal{new} new-placement\opt new-type-id new-initializer\opt \br
-    \terminal{::}\opt \terminal{new} new-placement\opt \terminal{(} type-id \terminal{)} new-initializer\opt
+    \terminal{::}\opt{} \terminal{new} new-placement\opt new-type-id new-initializer\opt \br
+    \terminal{::}\opt{} \terminal{new} new-placement\opt{} \terminal{(} type-id \terminal{)} new-initializer\opt
 \end{bnf}
 
 \indextext{\idxcode{new}!storage allocation}%
@@ -2846,7 +2846,7 @@
 
 \begin{bnf}
 \nontermdef{new-initializer}\br
-    \terminal{(} expression-list\opt \terminal{)}\br
+    \terminal{(} expression-list\opt{} \terminal{)}\br
     braced-init-list
 \end{bnf}
 
@@ -3322,8 +3322,8 @@
 
 \begin{bnf}
 \nontermdef{delete-expression}\br
-    \terminal{::}\opt \terminal{delete} cast-expression\br
-    \terminal{::}\opt \terminal{delete [ ]} cast-expression
+    \terminal{::}\opt{} \terminal{delete} cast-expression\br
+    \terminal{::}\opt{} \terminal{delete [ ]} cast-expression
 \end{bnf}
 
 The first alternative is for non-array objects, and the second is for arrays. Whenever