Add support for DMD 2.094 -preview=in switch

source/diet/defs.d

@@ -27,7 +27,7 @@ alias DietParserException = Exception;
 		Throws a `DietParserException` when called with a `false` condition at
 		run time.
 */
-void enforcep(bool cond, lazy string text, in ref Location loc) @safe
+void enforcep(bool cond, lazy string text, in Location loc) @safe
 {
 	if (__ctfe) {
 		import std.conv : to;

source/diet/dom.d

@@ -163,7 +163,7 @@ NodeContent[] toNodeContent(in AttributeContent[] contents, Location loc)
 			text = The text to append to the node
 			loc = Location in the source file
 	*/
-	void addText(string text, in ref Location loc)
+	void addText(string text, in Location loc)
 	{
 		if (contents.length && contents[$-1].kind == NodeContent.Kind.text && contents[$-1].loc == loc)
 			contents[$-1].value ~= text;
@@ -405,7 +405,7 @@ struct NodeContent {
 	}
 
 	/// Compares node content for equality.
-	bool opEquals(in ref NodeContent other)
+	bool opEquals(const scope ref NodeContent other)
 	const {
 		if (this.kind != other.kind) return false;
 		if (this.loc != other.loc) return false;

source/diet/html.d

@@ -717,7 +717,7 @@ private string getDoctypeMixin(ref CTX ctx, in Node node) @safe
 	return ctx.rawText(node.loc, "<"~doctype_str~">");
 }
 
-private string getCodeMixin(ref CTX ctx, in ref Node node, bool in_pre) @safe
+private string getCodeMixin(ref CTX ctx, const ref Node node, bool in_pre) @safe
 {
 	enforcep(node.attributes.length == 0, "Code lines may not have attributes.", node.loc);
 	enforcep(node.attribs == NodeAttribs.none, "Code lines may not specify translation or text block suffixes.", node.loc);
@@ -741,7 +741,7 @@ private string getCodeMixin(ref CTX ctx, in ref Node node, bool in_pre) @safe
 	return ret;
 }
 
-private string getCommentMixin(ref CTX ctx, in ref Node node) @safe
+private string getCommentMixin(ref CTX ctx, const ref Node node) @safe
 {
 	string ret = ctx.rawText(node.loc, "<!--");
 	ctx.depth++;

source/diet/internal/string.d

@@ -38,7 +38,7 @@ string dstringEscape(char ch)
 	}
 }
 
-string dstringEscape(in ref string str)
+string dstringEscape(in string str)
 {
 	string ret;
 	foreach( ch; str ) ret ~= dstringEscape(ch);

source/diet/parser.d

@@ -672,8 +672,8 @@ Document parseDiet(alias TR = identity)(const(InputFile)[] files)
 string identity(string str) nothrow @safe @nogc { return str; }
 
 
-private string parseIdent(in ref string str, ref size_t start,
-	   	string breakChars, in ref Location loc)
+private string parseIdent(in string str, ref size_t start,
+	   	string breakChars, in Location loc)
 @safe {
 	import std.array : back;
 	/* The stack is used to keep track of opening and
@@ -1340,7 +1340,7 @@ private string skipLine(ref string input, ref Location loc)
 	return ret;
 }
 
-private void parseAttributes(ref string input, ref size_t i, ref Node node, in ref Location loc)
+private void parseAttributes(ref string input, ref size_t i, ref Node node, in Location loc)
 @safe {
 	assert(i < input.length && input[i] == '(');
 	i++;
@@ -1384,7 +1384,7 @@ private void parseAttributes(ref string input, ref size_t i, ref Node node, in r
 	i++;
 }
 
-private void parseAttributeText(string input, ref AttributeContent[] dst, in ref Location loc)
+private void parseAttributeText(string input, ref AttributeContent[] dst, in Location loc)
 @safe {
 	size_t sidx = 0, idx = 0;
 
@@ -1421,7 +1421,7 @@ private void parseAttributeText(string input, ref AttributeContent[] dst, in ref
 	input = input[idx .. $];
 }
 
-private string skipUntilClosingBrace(in ref string s, ref size_t idx, in ref Location loc)
+private string skipUntilClosingBrace(in string s, ref size_t idx, in Location loc)
 @safe {
 	import std.algorithm.comparison : among;
 
@@ -1438,7 +1438,7 @@ private string skipUntilClosingBrace(in ref string s, ref size_t idx, in ref Loc
 	assert(false);
 }
 
-private string skipUntilClosingBracket(in ref string s, ref size_t idx, in ref Location loc)
+private string skipUntilClosingBracket(in string s, ref size_t idx, in Location loc)
 @safe {
 	import std.algorithm.comparison : among;
 
@@ -1455,7 +1455,8 @@ private string skipUntilClosingBracket(in ref string s, ref size_t idx, in ref L
 	assert(false);
 }
 
-private string skipIdent(in ref string s, ref size_t idx, string additional_chars, in ref Location loc, bool accept_empty = false, bool require_alpha_start = false)
+private string skipIdent(in string s, ref size_t idx, string additional_chars,
+	in Location loc, bool accept_empty = false, bool require_alpha_start = false)
 @safe {
 	import std.ascii : isAlpha;
 
@@ -1494,7 +1495,7 @@ private string skipIndent(ref string input)
 
 private bool isIndentChar(dchar ch) @safe { return ch == ' ' || ch == '\t'; }
 
-private string skipAnyWhitespace(in ref string s, ref size_t idx)
+private string skipAnyWhitespace(in string s, ref size_t idx)
 @safe {
 	import std.ascii : isWhite;
 
@@ -1562,7 +1563,7 @@ private bool isStringLiteral(string str)
 	assert(!isStringLiteral(`"name" value="#{name}"`));
 }
 
-private string skipExpression(in ref string s, ref size_t idx, in ref Location loc, bool multiline = false)
+private string skipExpression(in string s, ref size_t idx, in Location loc, bool multiline = false)
 @safe {
 	string clamp_stack;
 	size_t start = idx;
@@ -1599,7 +1600,8 @@ private string skipExpression(in ref string s, ref size_t idx, in ref Location l
 	return ctstrip(s[start .. idx]);
 }
 
-private string skipAttribString(in ref string s, ref size_t idx, char delimiter, in ref Location loc)
+
+private string skipAttribString(in string s, ref size_t idx, char delimiter, in Location loc)
 @safe {
 	size_t start = idx;
 	while( idx < s.length ){