From 01d2dc62670119c262607016ab60e61befaee567 Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Fri, 17 Sep 2021 19:31:28 +0100
Subject: Add utils for trimming string_views ltrim,rtrim,trim

---
 libadhocutil/strUtil.h                 | 29 ++++++++++++++++++++++
 libadhocutil/unittests/Jamfile.jam     |  1 +
 libadhocutil/unittests/testStrUtil.cpp | 45 ++++++++++++++++++++++++++++++++++
 3 files changed, 75 insertions(+)
 create mode 100644 libadhocutil/strUtil.h
 create mode 100644 libadhocutil/unittests/testStrUtil.cpp

diff --git a/libadhocutil/strUtil.h b/libadhocutil/strUtil.h
new file mode 100644
index 0000000..b366305
--- /dev/null
+++ b/libadhocutil/strUtil.h
@@ -0,0 +1,29 @@
+#include <string_view>
+
+namespace AdHoc {
+	constexpr auto &
+	rtrim(std::string_view & in, const auto c)
+	{
+		if (const auto n = in.find_last_not_of(c); n != std::string_view::npos) {
+			in.remove_suffix(in.length() - n - 1);
+		}
+		return in;
+	}
+
+	constexpr auto &
+	ltrim(std::string_view & in, const auto c)
+	{
+		if (const auto n = in.find_first_not_of(c); n != std::string_view::npos) {
+			in.remove_prefix(n);
+		}
+		return in;
+	}
+
+	constexpr auto &
+	trim(std::string_view & in, const auto c)
+	{
+		ltrim(in, c);
+		rtrim(in, c);
+		return in;
+	}
+}
diff --git a/libadhocutil/unittests/Jamfile.jam b/libadhocutil/unittests/Jamfile.jam
index 926c4cc..adb2645 100644
--- a/libadhocutil/unittests/Jamfile.jam
+++ b/libadhocutil/unittests/Jamfile.jam
@@ -348,3 +348,4 @@ run
 	<library>boost_utf
 	;
 
+obj testStrUtil : testStrUtil.cpp : <use>..//adhocutil ;
diff --git a/libadhocutil/unittests/testStrUtil.cpp b/libadhocutil/unittests/testStrUtil.cpp
new file mode 100644
index 0000000..fa642a7
--- /dev/null
+++ b/libadhocutil/unittests/testStrUtil.cpp
@@ -0,0 +1,45 @@
+#include <strUtil.h>
+
+constexpr auto
+ltrim(std::string_view s, const auto c)
+{
+	return AdHoc::ltrim(s, c);
+}
+constexpr auto
+rtrim(std::string_view s, const auto c)
+{
+	return AdHoc::rtrim(s, c);
+}
+constexpr auto
+trim(std::string_view s, const auto c)
+{
+	return AdHoc::trim(s, c);
+}
+
+static_assert(ltrim("foobar", 'r') == "foobar");
+static_assert(rtrim("foobar", 'r') == "fooba");
+static_assert(ltrim("foobar", 'f') == "oobar");
+static_assert(rtrim("foobar", 'f') == "foobar");
+
+static_assert(ltrim("foobar", "r") == "foobar");
+static_assert(rtrim("foobar", "r") == "fooba");
+static_assert(ltrim("foobar", "f") == "oobar");
+static_assert(rtrim("foobar", "f") == "foobar");
+
+static_assert(ltrim("foobar", "fo") == "bar");
+static_assert(ltrim("foobar", "of") == "bar");
+static_assert(rtrim("foobar", "fo") == "foobar");
+static_assert(rtrim("foobar", "of") == "foobar");
+
+static_assert(ltrim("foobar", "ar") == "foobar");
+static_assert(ltrim("foobar", "ra") == "foobar");
+static_assert(rtrim("foobar", "ar") == "foob");
+static_assert(rtrim("foobar", "ra") == "foob");
+
+static_assert(trim("roobar", 'r') == "ooba");
+static_assert(trim("foobar", 'r') == "fooba");
+static_assert(trim("foobar", 'f') == "oobar");
+static_assert(trim("foobar", "f") == "oobar");
+static_assert(trim("foobar", "r") == "fooba");
+static_assert(trim("foobar", "fr") == "ooba");
+static_assert(trim("foobar", "ofr") == "ba");
-- 
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