fs/Traits: add Find()

src/fs/Path.hxx

@@ -129,7 +129,7 @@ public:
 	 */
 	gcc_pure
 	bool HasNewline() const {
-		return strchr(value, '\n') != nullptr;
+		return PathTraitsFS::Find(value, '\n') != nullptr;
 	}
 
 	/**

src/fs/Traits.hxx

@@ -101,6 +101,16 @@ struct PathTraitsFS {
 		return char_traits::length(p);
 	}
 
+	gcc_pure gcc_nonnull_all
+	static const_pointer Find(const_pointer p, size_t n, value_type ch) {
+		return char_traits::find(p, n, ch);
+	}
+
+	gcc_pure gcc_nonnull_all
+	static const_pointer Find(const_pointer p, value_type ch) {
+		return strchr(p, ch);
+	}
+
 	/**
 	 * Determine the "base" file name of the given native path.
 	 * The return value points inside the given string.
@@ -195,6 +205,16 @@ struct PathTraitsUTF8 {
 		return char_traits::length(p);
 	}
 
+	gcc_pure gcc_nonnull_all
+	static const_pointer Find(const_pointer p, size_t n, value_type ch) {
+		return char_traits::find(p, n, ch);
+	}
+
+	gcc_pure gcc_nonnull_all
+	static const_pointer Find(const_pointer p, value_type ch) {
+		return strchr(p, ch);
+	}
+
 	/**
 	 * Determine the "base" file name of the given UTF-8 path.
 	 * The return value points inside the given string.