From 296fd9183be847960c0d71be68a2f47dc3aad665 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Thu, 14 Sep 2017 13:01:06 -0700
Subject: [PATCH] ircd::util: Add ctype() template for testing string ranges.

---
 include/ircd/string_view.h |  8 ++++++++
 include/ircd/util.h        | 15 +++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/include/ircd/string_view.h b/include/ircd/string_view.h
index 5e948f102..929dae691 100644
--- a/include/ircd/string_view.h
+++ b/include/ircd/string_view.h
@@ -32,6 +32,7 @@ namespace ircd
 	template<class T> struct vector_view;
 	template<class T = string_view> struct byte_view;
 	template<> struct byte_view<string_view>;
+	template<int (&test)(int) = std::isprint> auto ctype(const string_view &s);
 
 	bool operator!(const string_view &);
 }
@@ -241,3 +242,10 @@ ircd::operator!(const string_view &str)
 {
 	return str.empty();
 }
+
+template<int (&test)(int)>
+auto
+ircd::ctype(const string_view &s)
+{
+    return ctype<test>(std::begin(s), std::end(s));
+}
diff --git a/include/ircd/util.h b/include/ircd/util.h
index feaded6c2..90d72fa59 100644
--- a/include/ircd/util.h
+++ b/include/ircd/util.h
@@ -1037,5 +1037,20 @@ until(it_a a,
 }
 
 
+/// Convenience loop to test std::is* on a character sequence
+template<int (&test)(int) = std::isprint>
+ssize_t
+ctype(const char *begin,
+      const char *const &end)
+{
+	size_t i(0);
+	for(; begin != end; ++begin, ++i)
+		if(!test(static_cast<unsigned char>(*begin)))
+			return i;
+
+	return -1;
+}
+
+
 } // namespace util
 } // namespace ircd