From a112c8e67b74c4044344006947d6d377b277d26f Mon Sep 17 00:00:00 2001
From: arvidn <arvid@libtorrent.org>
Date: Wed, 12 Dec 2018 09:28:19 +0100
Subject: [PATCH] add assignment operator to span

---
 include/libtorrent/span.hpp |  9 +++++++++
 test/test_span.cpp          | 19 +++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/include/libtorrent/span.hpp b/include/libtorrent/span.hpp
index 1ff8776df..72dbbd03d 100644
--- a/include/libtorrent/span.hpp
+++ b/include/libtorrent/span.hpp
@@ -108,6 +108,15 @@ namespace aux {
 		span(Cont const& c) // NOLINT
 			: m_ptr(c.data()), m_len(static_cast<difference_type>(c.size())) {}
 
+		template <typename U, typename
+			= typename std::enable_if<aux::compatible_type<U, T>::value>::type>
+		span& operator=(span<U> const& rhs) noexcept
+		{
+			m_ptr = rhs.data();
+			m_len = rhs.size();
+			return *this;
+		}
+
 		index_type size() const noexcept { return m_len; }
 		bool empty() const noexcept { return m_len == 0; }
 		T* data() const noexcept { return m_ptr; }
diff --git a/test/test_span.cpp b/test/test_span.cpp
index 1f4add6ea..a7a0420f9 100644
--- a/test/test_span.cpp
+++ b/test/test_span.cpp
@@ -56,6 +56,25 @@ TORRENT_TEST(span_vector)
 	TEST_CHECK(a.size() == 4);
 }
 
+TORRENT_TEST(span_vector_assignment)
+{
+	std::vector<char> v1 = {1,2,3,4};
+	span<char> a;
+	a = v1;
+	TEST_CHECK(a == f(v1));
+	TEST_CHECK(a.size() == 4);
+}
+
+TORRENT_TEST(span_assignment)
+{
+	char v1[] = {1,2,3,4};
+	span<char> a2(v1);
+	span<char> a;
+	a = a2;
+	TEST_CHECK(a == f(v1));
+	TEST_CHECK(a.size() == 4);
+}
+
 namespace {
 
 void do_span_temp_vector(span<char const> a)