support negative First set calculation for unicode properties

Author: Hana Dusíková

include/ctre/first.hpp

@@ -319,6 +319,16 @@ template <typename CB> constexpr int64_t negative_helper(ctre::set<>, CB &, int6
 	return start;
 }
 
+template <auto Property, typename CB> 
+constexpr auto negative_helper(ctre::binary_property<Property>, CB &&, int64_t start) {
+	return start;
+}
+
+template <auto Property, auto Value, typename CB> 
+constexpr auto negative_helper(ctre::property<Property, Value>, CB &&, int64_t start) {
+	return start;
+}
+
 template <typename Head, typename... Rest, typename CB> constexpr int64_t negative_helper(ctre::set<Head, Rest...>, CB & cb, int64_t start) {
 	start = negative_helper(Head{}, cb, start);
 	return negative_helper(ctre::set<Rest...>{}, cb, start);

tests/_unicode.cpp

@@ -60,6 +60,9 @@ static_assert(CTRE_CREATE(U"\\u20AC").match(U"€"));
 // TODO only \p and \P is not supported
 static_assert(CTRE_SYNTAX(U"\\p{L}"));
 static_assert(CTRE_SYNTAX(U"\\p{Letter}"));
+static_assert(CTRE_CREATE(U"\\P{Letter}").match(U"1"));
+static_assert(CTRE_CREATE(U"\\P{latin}").match(U"Є"));
+static_assert(CTRE_CREATE(U"[^\\p{latin}\\p{script=Greek}]").match(U"ש"));
 static_assert(CTRE_CREATE(U"\\p{Letter}+").match(u8"abcDEF"));
 static_assert(CTRE_CREATE(U"\\p{Letter}+").match(U"abcDEF"));
 static_assert(CTRE_CREATE(U"\\p{Ll}+").match(U"abcdef"));