add InterfaceDetails.isEmpty

source/workspaced/dparseext.d

@@ -415,3 +415,23 @@ unittest
 	assert(getIfElse(p("if (x) {} else if (y) {} else {}")) !is null);
 	assert(cast(IfStatement)getIfElse(p("if (x) {} else if (y) {} else {}")) is null);
 }
+
+C[] substr(C)(C[] s, size_t[2] range)
+{
+	return substr(s, range[0], range[1]);
+}
+
+C[] substr(C)(C[] s, size_t start, size_t end)
+{
+	if (!s.length)
+		return s;
+	if (start < 0)
+		start = 0;
+	if (start >= s.length)
+		start = s.length - 1; // @suppress(dscanner.suspicious.length_subtraction)
+	if (end > s.length)
+		end = s.length;
+	if (end < start)
+		return s[start .. start];
+	return s[start .. end];
+}

source/workspaced/visitors/methodfinder.d

@@ -130,6 +130,12 @@ struct InterfaceDetails
 	size_t[2] blockRange;
 	/// A (name-based) sorted set of referenced types with first occurences of every type or alias not including built-in types, but including object.d types and aliases.
 	ReferencedType[] referencedTypes;
+
+	/// Returns true if there are no non-whitespace characters inside the block.
+	bool isEmpty() const
+	{
+		return !code.substr(blockRange).strip.length;
+	}
 }
 
 class InterfaceMethodFinder : AttributesVisitor