Add test::fail_count to experimental

include/boost/beast/experimental/core/ssl_stream.hpp

@@ -250,7 +250,7 @@ public:
         This function may be used to configure the peer verification mode used by
         the stream. The new mode will override the mode inherited from the context.
         
-        @param v A bitmask of peer verification modes. See @ref verify_mode for
+        @param v A bitmask of peer verification modes. See `verify_mode` for
         available values.
         
         @param ec Set to indicate what error occurred, if any.

include/boost/beast/experimental/test/fail_count.hpp

@@ -0,0 +1,65 @@
+//
+// Copyright (c) 2016-2017 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// Official repository: https://github.com/boostorg/beast
+//
+
+#ifndef BOOST_BEAST_TEST_FAIL_COUNT_HPP
+#define BOOST_BEAST_TEST_FAIL_COUNT_HPP
+
+#include <boost/beast/core/error.hpp>
+#include <boost/beast/experimental/test/error.hpp>
+#include <boost/throw_exception.hpp>
+
+namespace boost {
+namespace beast {
+namespace test {
+
+/** A countdown to simulated failure
+
+    On the Nth operation, the class will fail with the specified
+    error code, or the default error code of @ref error::test_failure.
+
+    Instances of this class may be used to build objects which
+    are specifically designed to aid in writing unit tests, for
+    interfaces which can throw exceptions or return `error_code`
+    values representing failure.
+*/
+class fail_count
+{
+    std::size_t n_;
+    std::size_t i_ = 0;
+    error_code ec_;
+
+public:
+    fail_count(fail_count&&) = default;
+
+    /** Construct a counter
+
+        @param n The 0-based index of the operation to fail on or after
+        @param ev An optional error code to use when generating a simulated failure
+    */
+    explicit
+    fail_count(
+        std::size_t n,
+        error_code ev = make_error_code(error::test_failure));
+
+    /// Throw an exception on the Nth failure
+    void
+    fail();
+
+    /// Set an error code on the Nth failure
+    bool
+    fail(error_code& ec);
+};
+
+} // test
+} // beast
+} // boost
+
+#include <boost/beast/experimental/test/impl/fail_count.ipp>
+
+#endif

include/boost/beast/experimental/test/impl/fail_count.ipp

@@ -0,0 +1,62 @@
+//
+// Copyright (c) 2016-2017 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// Official repository: https://github.com/boostorg/beast
+//
+
+#ifndef BOOST_BEAST_TEST_IMPL_FAIL_COUNT_IPP
+#define BOOST_BEAST_TEST_IMPL_FAIL_COUNT_IPP
+
+#include <boost/beast/core/error.hpp>
+#include <boost/beast/experimental/test/error.hpp>
+#include <boost/throw_exception.hpp>
+
+namespace boost {
+namespace beast {
+namespace test {
+
+inline
+fail_count::
+fail_count(
+    std::size_t n,
+    error_code ev)
+    : n_(n)
+    , ec_(ev)
+{
+}
+
+inline
+void
+fail_count::
+fail()
+{
+    if(i_ < n_)
+        ++i_;
+    if(i_ == n_)
+        BOOST_THROW_EXCEPTION(system_error{ec_});
+}
+
+inline
+bool
+fail_count::
+fail(error_code& ec)
+{
+    if(i_ < n_)
+        ++i_;
+    if(i_ == n_)
+    {
+        ec = ec_;
+        return true;
+    }
+    ec.assign(0, ec.category());
+    return false;
+}
+
+} // test
+} // beast
+} // boost
+
+#endif