Add TriState::empty()

Author: asfernandes

src/common/classes/TriState.h

@@ -34,8 +34,14 @@ namespace Firebird {
 class TriState
 {
 public:
-	TriState() noexcept;
-	explicit TriState(bool input) noexcept;
+	static constexpr TriState empty() noexcept
+	{
+		return TriState();
+	}
+
+public:
+	constexpr TriState() noexcept;
+	explicit constexpr TriState(bool input) noexcept;
 
 	bool operator ==(const TriState& o) const noexcept
 	{
@@ -62,13 +68,13 @@ class TriState
 };
 
 // The var is left uninitialized.
-inline TriState::TriState() noexcept
+inline constexpr TriState::TriState() noexcept
 	: m_init(false), m_val(false)
 {
 }
 
 // The var is initialized to the explicit value.
-inline TriState::TriState(bool input) noexcept
+inline constexpr TriState::TriState(bool input) noexcept
 	: m_init(true), m_val(input)
 {
 }

src/dsql/parse.y

@@ -2395,7 +2395,7 @@ sql_security_clause
 
 %type <triState> sql_security_clause_opt
 sql_security_clause_opt
-	: /* nothing */				{ $$ = TriState(); }
+	: /* nothing */				{ $$ = TriState::empty(); }
 	| sql_security_clause		{ $$ = $1; }
 	;
 
@@ -4244,7 +4244,7 @@ trigger_active
 	| INACTIVE
 		{ $$ = TriState(false); }
 	| // nothing
-		{ $$ = TriState(); }
+		{ $$ = TriState::empty(); }
 	;
 
 %type <uint64Val> trigger_type(<createAlterTriggerNode>)
@@ -4590,7 +4590,7 @@ alter_op($relationNode)
 		}
 	| DROP SQL SECURITY
 		{
-			setClause($relationNode->ssDefiner, "SQL SECURITY", TriState());
+			setClause($relationNode->ssDefiner, "SQL SECURITY", TriState::empty());
 			RelationNode::Clause* clause =
 				newNode<RelationNode::Clause>(RelationNode::Clause::TYPE_ALTER_SQL_SECURITY);
 			$relationNode->clauses.add(clause);
@@ -6321,7 +6321,7 @@ optimize_clause
 	: OPTIMIZE optimize_mode
 		{ $$ = TriState($2); }
 	| // nothing
-		{ $$ = TriState(); }
+		{ $$ = TriState::empty(); }
 	;
 
 %type <boolVal> optimize_mode

src/jrd/jrd.cpp

@@ -1860,7 +1860,7 @@ JAttachment* JProvider::internalAttach(CheckStatusWrapper* user_status, const ch
 				// The actual FW mode (if different) will be fixed afterwards by PIO_header().
 
 				const TriState newForceWrite = options.dpb_set_force_write ?
-					TriState(options.dpb_force_write) : TriState();
+					TriState(options.dpb_force_write) : TriState::empty();
 
 				// Set the FW flag inside the database block to be considered by PIO routines
 				if (newForceWrite.valueOr(true))

src/jrd/pag_proto.h

@@ -45,7 +45,7 @@ bool	PAG_delete_clump_entry(Jrd::thread_db* tdbb, USHORT);
 void	PAG_format_header(Jrd::thread_db*);
 void	PAG_format_pip(Jrd::thread_db*, Jrd::PageSpace& pageSpace);
 bool	PAG_get_clump(Jrd::thread_db*, USHORT, USHORT*, UCHAR*);
-void	PAG_header(Jrd::thread_db*, bool, const Firebird::TriState newForceWrite = Firebird::TriState());
+void	PAG_header(Jrd::thread_db*, bool, const Firebird::TriState newForceWrite = Firebird::TriState::empty());
 void	PAG_header_init(Jrd::thread_db*);
 void	PAG_init(Jrd::thread_db*);
 void	PAG_init2(Jrd::thread_db*);