From c7dfa29f297d2b09f1a7c9c17d63f6030f094a11 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@gmail.com>
Date: Wed, 6 Oct 2021 04:35:37 +0300
Subject: [PATCH] Add sv_starts_with_test

---
 include/boost/core/string_view.hpp | 12 +++++++
 test/Jamfile.v2                    |  1 +
 test/sv_starts_with_test.cpp       | 50 ++++++++++++++++++++++++++++++
 3 files changed, 63 insertions(+)
 create mode 100644 test/sv_starts_with_test.cpp

diff --git a/include/boost/core/string_view.hpp b/include/boost/core/string_view.hpp
index ae71d72..3117e7d 100644
--- a/include/boost/core/string_view.hpp
+++ b/include/boost/core/string_view.hpp
@@ -563,6 +563,18 @@ public:
     {
         return find( s ) != npos;
     }
+
+    // relational operators
+
+    BOOST_CONSTEXPR friend bool operator==( basic_string_view sv1, basic_string_view sv2 ) BOOST_NOEXCEPT
+    {
+        return sv1.compare( sv2 ) == 0;
+    }
+
+    BOOST_CONSTEXPR friend bool operator!=( basic_string_view sv1, basic_string_view sv2 ) BOOST_NOEXCEPT
+    {
+        return sv1.compare( sv2 ) != 0;
+    }
 };
 
 #if defined(BOOST_NO_CXX17_INLINE_VARIABLES)
diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index f174ba2..fb6d452 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -254,6 +254,7 @@ run sv_modifiers_test.cpp ;
 run sv_copy_test.cpp ;
 run sv_substr_test.cpp ;
 run sv_compare_test.cpp ;
+run sv_starts_with_test.cpp ;
 
 use-project /boost/core/swap : ./swap ;
 build-project ./swap ;
diff --git a/test/sv_starts_with_test.cpp b/test/sv_starts_with_test.cpp
new file mode 100644
index 0000000..e3d69c5
--- /dev/null
+++ b/test/sv_starts_with_test.cpp
@@ -0,0 +1,50 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/core/string_view.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <stdexcept>
+#include <cstddef>
+
+int main()
+{
+    {
+        boost::core::string_view sv( "" );
+
+        BOOST_TEST( sv.starts_with( boost::core::string_view() ) );
+        BOOST_TEST( sv.starts_with( boost::core::string_view( "" ) ) );
+        BOOST_TEST( sv.starts_with( "" ) );
+
+        BOOST_TEST( !sv.starts_with( boost::core::string_view( "1" ) ) );
+        BOOST_TEST( !sv.starts_with( '1' ) );
+        BOOST_TEST( !sv.starts_with( "1" ) );
+    }
+
+    {
+        boost::core::string_view sv( "123" );
+
+        BOOST_TEST( sv.starts_with( boost::core::string_view() ) );
+        BOOST_TEST( sv.starts_with( boost::core::string_view( "" ) ) );
+        BOOST_TEST( sv.starts_with( "" ) );
+
+        BOOST_TEST( sv.starts_with( boost::core::string_view( "1" ) ) );
+        BOOST_TEST( sv.starts_with( '1' ) );
+        BOOST_TEST( sv.starts_with( "1" ) );
+
+        BOOST_TEST( sv.starts_with( boost::core::string_view( "12" ) ) );
+        BOOST_TEST( sv.starts_with( "12" ) );
+
+        BOOST_TEST( sv.starts_with( boost::core::string_view( "123" ) ) );
+        BOOST_TEST( sv.starts_with( "123" ) );
+
+        BOOST_TEST( !sv.starts_with( boost::core::string_view( "1234" ) ) );
+        BOOST_TEST( !sv.starts_with( "1234" ) );
+
+        BOOST_TEST( !sv.starts_with( boost::core::string_view( "2" ) ) );
+        BOOST_TEST( !sv.starts_with( '2' ) );
+        BOOST_TEST( !sv.starts_with( "2" ) );
+    }
+
+    return boost::report_errors();
+}