Add <boost/system/result.hpp>

test/result_move_assign.cpp

@@ -0,0 +1,441 @@
+// Copyright 2017, 2021 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/result/result.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
+#include <system_error>
+#include <iosfwd>
+#include <cerrno>
+
+using namespace boost::result;
+
+struct X
+{
+    static int instances;
+
+    int v_;
+
+    explicit X( int v = 0 ): v_( v ) { ++instances; }
+
+    X( X const& r ) = delete;
+    X( X&& r ): v_( r.v_ ) { r.v_ = 0; ++instances; }
+
+    X& operator=( X const& ) = delete;
+
+    X& operator=( X&& r )
+    {
+        v_ = r.v_;
+        r.v_ = 0;
+
+        return *this;
+    }
+
+    ~X() { --instances; }
+};
+
+bool operator==( X const & x1, X const & x2 )
+{
+    return x1.v_ == x2.v_;
+}
+
+std::ostream& operator<<( std::ostream& os, X const & x )
+{
+    os << "X:" << x.v_;
+    return os;
+}
+
+int X::instances = 0;
+
+struct Y
+{
+    static int instances;
+
+    int v_;
+
+    explicit Y( int v = 0 ): v_( v ) { ++instances; }
+
+    Y( Y const& r ) noexcept: v_( r.v_ ) { ++instances; }
+    Y( Y&& r ) noexcept: v_( r.v_ ) { r.v_ = 0; ++instances; }
+
+    Y& operator=( Y const& ) = default;
+
+    Y& operator=( Y&& r )
+    {
+        v_ = r.v_;
+        r.v_ = 0;
+
+        return *this;
+    }
+
+    ~Y() { --instances; }
+};
+
+bool operator==( Y const & y1, Y const & y2 )
+{
+    return y1.v_ == y2.v_;
+}
+
+std::ostream& operator<<( std::ostream& os, Y const & y )
+{
+    os << "Y:" << y.v_;
+    return os;
+}
+
+int Y::instances = 0;
+
+int main()
+{
+    // default-initialized lhs
+
+    {
+        result<int> r;
+        result<int> r2;
+
+        r2 = std::move( r );
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST( !r2.has_error() );
+
+        BOOST_TEST_EQ( r2.value(), 0 );
+    }
+
+    {
+        result<int> r;
+        result<int> r2( 1 );
+
+        r2 = std::move( r );
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST( !r2.has_error() );
+
+        BOOST_TEST_EQ( r2.value(), 0 );
+    }
+
+    {
+        result<int> r;
+        result<int> r2( ENOENT, std::generic_category() );
+
+        r2 = std::move( r );
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST( !r2.has_error() );
+
+        BOOST_TEST_EQ( r2.value(), 0 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<X> r;
+        result<X> r2;
+
+        BOOST_TEST_EQ( X::instances, 2 );
+
+        r2 = std::move( r );
+
+        BOOST_TEST_EQ( X::instances, 2 );
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST( !r2.has_error() );
+
+        BOOST_TEST_EQ( r2.value(), X() );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<X> r;
+        result<X> r2( 1 );
+
+        BOOST_TEST_EQ( X::instances, 2 );
+
+        r2 = std::move( r );
+
+        BOOST_TEST_EQ( X::instances, 2 );
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST( !r2.has_error() );
+
+        BOOST_TEST_EQ( r2.value(), X() );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<X> r;
+        result<X> r2( ENOENT, std::generic_category() );
+
+        BOOST_TEST_EQ( X::instances, 1 );
+
+        r2 = std::move( r );
+
+        BOOST_TEST_EQ( X::instances, 2 );
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST( !r2.has_error() );
+
+        BOOST_TEST_EQ( r2.value(), X() );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    // value lhs
+
+    {
+        result<int> r( 1 );
+        result<int> r2;
+
+        r2 = std::move( r );
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST( !r2.has_error() );
+
+        BOOST_TEST_EQ( r2.value(), 1 );
+
+        BOOST_TEST_EQ( r, r2 );
+    }
+
+    {
+        result<int> r( 1 );
+        result<int> r2( 2 );
+
+        r2 = std::move( r );
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST( !r2.has_error() );
+
+        BOOST_TEST_EQ( r2.value(), 1 );
+
+        BOOST_TEST_EQ( r, r2 );
+    }
+
+    {
+        result<int> r( 1 );
+        result<int> r2( ENOENT, std::generic_category() );
+
+        r2 = std::move( r );
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST( !r2.has_error() );
+
+        BOOST_TEST_EQ( r2.value(), 1 );
+
+        BOOST_TEST_EQ( r, r2 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<X> r( 1 );
+        result<X> r2;
+
+        BOOST_TEST_EQ( X::instances, 2 );
+
+        r2 = std::move( r );
+
+        BOOST_TEST_EQ( X::instances, 2 );
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST( !r2.has_error() );
+
+        BOOST_TEST_EQ( r2.value().v_, 1 );
+
+        BOOST_TEST_EQ( r.value().v_, 0 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<X> r( 1 );
+        result<X> r2( 2 );
+
+        BOOST_TEST_EQ( X::instances, 2 );
+
+        r2 = std::move( r );
+
+        BOOST_TEST_EQ( X::instances, 2 );
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST( !r2.has_error() );
+
+        BOOST_TEST_EQ( r2.value().v_, 1 );
+
+        BOOST_TEST_EQ( r.value().v_, 0 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<X> r( 1 );
+        result<X> r2( ENOENT, std::generic_category() );
+
+        BOOST_TEST_EQ( X::instances, 1 );
+
+        r2 = std::move( r );
+
+        BOOST_TEST_EQ( X::instances, 2 );
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST( !r2.has_error() );
+
+        BOOST_TEST_EQ( r2.value().v_, 1 );
+
+        BOOST_TEST_EQ( r.value().v_, 0 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    // error lhs
+
+    {
+        auto ec = make_error_code( std::errc::invalid_argument );
+
+        result<int> r( ec );
+        result<int> r2;
+
+        r2 = std::move( r );
+
+        BOOST_TEST( !r2.has_value() );
+        BOOST_TEST( r2.has_error() );
+
+        BOOST_TEST_EQ( r2.error(), ec );
+    }
+
+    {
+        auto ec = make_error_code( std::errc::invalid_argument );
+
+        result<int> r( ec );
+        result<int> r2( 1 );
+
+        r2 = std::move( r );
+
+        BOOST_TEST( !r2.has_value() );
+        BOOST_TEST( r2.has_error() );
+
+        BOOST_TEST_EQ( r2.error(), ec );
+    }
+
+    {
+        auto ec = make_error_code( std::errc::invalid_argument );
+
+        result<int> r( ec );
+        result<int> r2( ENOENT, std::generic_category() );
+
+        r2 = std::move( r );
+
+        BOOST_TEST( !r2.has_value() );
+        BOOST_TEST( r2.has_error() );
+
+        BOOST_TEST_EQ( r2.error(), ec );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        auto ec = make_error_code( std::errc::invalid_argument );
+
+        result<X> r( ec );
+        result<X> r2;
+
+        BOOST_TEST_EQ( X::instances, 1 );
+
+        r2 = std::move( r );
+
+        BOOST_TEST_EQ( X::instances, 0 );
+
+        BOOST_TEST( !r2.has_value() );
+        BOOST_TEST( r2.has_error() );
+
+        BOOST_TEST_EQ( r2.error(), ec );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        auto ec = make_error_code( std::errc::invalid_argument );
+
+        result<X> r( ec );
+        result<X> r2( 1 );
+
+        BOOST_TEST_EQ( X::instances, 1 );
+
+        r2 = std::move( r );
+
+        BOOST_TEST_EQ( X::instances, 0 );
+
+        BOOST_TEST( !r2.has_value() );
+        BOOST_TEST( r2.has_error() );
+
+        BOOST_TEST_EQ( r2.error(), ec );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        auto ec = make_error_code( std::errc::invalid_argument );
+
+        result<X> r( ec );
+        result<X> r2( ENOENT, std::generic_category() );
+
+        BOOST_TEST_EQ( X::instances, 0 );
+
+        r2 = std::move( r );
+
+        BOOST_TEST_EQ( X::instances, 0 );
+
+        BOOST_TEST( !r2.has_value() );
+        BOOST_TEST( r2.has_error() );
+
+        BOOST_TEST_EQ( r2.error(), ec );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    //
+
+    BOOST_TEST_EQ( Y::instances, 0 );
+
+    {
+        result<std::string, Y> r( 1 );
+        result<std::string, Y> r2( 2 );
+
+        BOOST_TEST_EQ( Y::instances, 2 );
+
+        r2 = std::move( r );
+
+        BOOST_TEST_EQ( Y::instances, 2 );
+
+        BOOST_TEST( !r2.has_value() );
+        BOOST_TEST( r2.has_error() );
+
+        BOOST_TEST_EQ( r2.error().v_, 1 );
+
+        BOOST_TEST_EQ( r.error().v_, 0 );
+    }
+
+    BOOST_TEST_EQ( Y::instances, 0 );
+
+    {
+        result<std::string, Y> r( 1 );
+        result<std::string, Y> r2( "str" );
+
+        BOOST_TEST_EQ( Y::instances, 1 );
+
+        r2 = std::move( r );
+
+        BOOST_TEST_EQ( Y::instances, 2 );
+
+        BOOST_TEST( !r2.has_value() );
+        BOOST_TEST( r2.has_error() );
+
+        BOOST_TEST_EQ( r2.error().v_, 1 );
+
+        BOOST_TEST_EQ( r.error().v_, 0 );
+    }
+
+    BOOST_TEST_EQ( Y::instances, 0 );
+
+    return boost::report_errors();
+}