leaf/test/try_exception_and_result_test.cpp

// Copyright (c) 2018-2019 Emil Dotchevski and Reverge Studios, Inc.

// 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)

#include <boost/leaf/handle_exception.hpp>
#include <boost/leaf/result.hpp>
#include "boost/core/lightweight_test.hpp"

namespace leaf = boost::leaf;

template <int> struct info { int value; };

struct my_exception: std::exception { };

int main()
{
	{
		leaf::result<int> r = leaf::try_handle_some(
			[]() -> leaf::result<int>
			{
				return 42;
			},
			[]
			{
				return 1;
			} );
		BOOST_TEST(r);
		BOOST_TEST_EQ(r.value(), 42);
	}
	{
		leaf::result<int> r = leaf::try_handle_some(
			[]() -> leaf::result<int>
			{
				throw leaf::exception( my_exception(), info<1>{1} );
			},
			[]( leaf::catch_<my_exception>, info<1> const & x )
			{
				BOOST_TEST_EQ(x.value, 1);
				return 42;
			} );
		BOOST_TEST(r);
		BOOST_TEST_EQ(r.value(), 42);
	}
	{
		leaf::result<int> r = leaf::try_handle_some(
			[]() -> leaf::result<int>
			{
				return leaf::new_error( info<1>{1} );
			},
			[]( info<1> const & x )
			{
				BOOST_TEST_EQ(x.value, 1);
				return -42;
			} );
		BOOST_TEST(r);
		BOOST_TEST_EQ(r.value(), -42);
	}

	{
		auto handle_error = []( leaf::error_info const & error )
		{
			return leaf::remote_handle_some( error,
				[]( leaf::catch_<my_exception>, info<1> const & x ) -> leaf::result<int>
				{
					BOOST_TEST_EQ(x.value, 1);
					return 42;
				},
				[]( info<1> const & x ) -> leaf::result<int>
				{
					BOOST_TEST_EQ(x.value, 1);
					return -42;
				} );
		};
		{
			leaf::result<int> r = leaf::remote_try_handle_some(
				[]() -> leaf::result<int>
				{
					return 42;
				},
				[&]( leaf::error_info const & error )
				{
					return handle_error(error);
				} );
			BOOST_TEST(r);
			BOOST_TEST_EQ(r.value(), 42);
		}
		{
			leaf::result<int> r = leaf::remote_try_handle_some(
				[]() -> leaf::result<int>
				{
					throw leaf::exception( my_exception(), info<1>{1} );
				},
				[&]( leaf::error_info const & error )
				{
					return handle_error(error);
				} );
			BOOST_TEST(r);
			BOOST_TEST_EQ(r.value(), 42);
		}
		{
			leaf::result<int> r = leaf::remote_try_handle_some(
				[]() -> leaf::result<int>
				{
					return leaf::new_error( info<1>{1} );
				},
				[&]( leaf::error_info const & error )
				{
					return handle_error(error);
				} );
			BOOST_TEST(r);
			BOOST_TEST_EQ(r.value(), -42);
		}
	}

	{
		int r = leaf::try_handle_all(
			[]() -> leaf::result<int>
			{
				return 42;
			},
			[]
			{
				return 1;
			} );
		BOOST_TEST_EQ(r, 42);
	}
	{
		int r = leaf::try_handle_all(
			[]() -> leaf::result<int>
			{
				throw leaf::exception( my_exception(), info<1>{1} );
			},
			[]( leaf::catch_<my_exception>, info<1> const & x )
			{
				BOOST_TEST_EQ(x.value, 1);
				return 42;
			},
			[]
			{
				return 1;
			} );
		BOOST_TEST_EQ(r, 42);
	}
	{
		int r = leaf::try_handle_all(
			[]() -> leaf::result<int>
			{
				return leaf::new_error( info<1>{1} );
			},
			[]( info<1> const & x )
			{
				BOOST_TEST_EQ(x.value, 1);
				return 42;
			},
			[]
			{
				return 1;
			} );
		BOOST_TEST_EQ(r, 42);
	}

	{
		auto handle_error = []( leaf::error_info const & error )
		{
			return leaf::remote_handle_all( error,
				[]( leaf::catch_<my_exception>, info<1> const & x )
				{
					BOOST_TEST_EQ(x.value, 1);
					return 42;
				},
				[]( info<1> const & x )
				{
					BOOST_TEST_EQ(x.value, 1);
					return -42;
				},
				[]
				{
					return 1;
				} );
		};
		{
			int r = leaf::remote_try_handle_all(
				[]() -> leaf::result<int>
				{
					return 42;
				},
				[&]( leaf::error_info const & error )
				{
					return handle_error(error);
				} );
			BOOST_TEST_EQ(r, 42);
		}
		{
			int r = leaf::remote_try_handle_all(
				[]() -> leaf::result<int>
				{
					throw leaf::exception( my_exception(), info<1>{1} );
				},
				[&]( leaf::error_info const & error )
				{
					return handle_error(error);
				} );
			BOOST_TEST_EQ(r, 42);
		}
		{
			int r = leaf::remote_try_handle_all(
				[]() -> leaf::result<int>
				{
					return leaf::new_error( info<1>{1} );
				},
				[&]( leaf::error_info const & error )
				{
					return handle_error(error);
				} );
			BOOST_TEST_EQ(r, -42);
		}
	}

	{
		int r = leaf::try_handle_all(
			[]() -> leaf::result<int>
			{
				return leaf::try_handle_all(
					[]() -> leaf::result<int>
					{
						return leaf::new_error( info<1>{1} );
					},
					[]( info<1> const & ) -> int
					{
						LEAF_THROW(my_exception());
					},
					[]( leaf::catch_<> )
					{
						return 1;
					},
					[]
					{
						return 2;
					} );
			},
			[]( leaf::catch_<> )
			{
				return 3;
			},
			[]
			{
				return 4;
			} );

		BOOST_TEST_EQ(r, 3);
	}

	{
		auto handle_error = []( leaf::error_info const & error )
		{
			return leaf::remote_handle_all( error,
				[]( info<1> const & ) -> int
				{
					LEAF_THROW(my_exception());
				},
				[]( leaf::catch_<> )
				{
					return 1;
				},
				[]
				{
					return 2;
				} );
		};
		int r = leaf::try_handle_all(
			[&]() -> leaf::result<int>
			{
				return leaf::remote_try_handle_all(
					[&]() -> leaf::result<int>
					{
						return leaf::new_error( info<1>{1} );
					},
					[&]( leaf::error_info const & error )
					{
						return handle_error(error);
					} );
			},
			[]( leaf::catch_<> )
			{
				return 3;
			},
			[]
			{
				return 4;
			} );

		BOOST_TEST_EQ(r, 3);
	}

	{
		int r = leaf::try_handle_all(
			[]() -> leaf::result<int>
			{
				return leaf::try_handle_some(
					[]() -> leaf::result<int>
					{
						return leaf::new_error( info<1>{1} );
					},
					[]( info<1> const & ) -> int
					{
						LEAF_THROW(my_exception());
					},
					[]( leaf::catch_<> )
					{
						return 1;
					} );
			},
			[]( leaf::catch_<> )
			{
				return 3;
			},
			[]
			{
				return 4;
			} );

		BOOST_TEST_EQ(r, 3);
	}

	{
		auto handle_error = []( leaf::error_info const & error )
		{
			return leaf::remote_handle_some( error,
				[]( info<1> const & ) -> leaf::result<int>
				{
					LEAF_THROW(my_exception());
				},
				[]( leaf::catch_<> ) -> leaf::result<int>
				{
					return 1;
				} );
		};
		int r = leaf::try_handle_all(
			[&]() -> leaf::result<int>
			{
				return leaf::remote_try_handle_some(
					[&]() -> leaf::result<int>
					{
						return leaf::new_error( info<1>{1} );
					},
					[&]( leaf::error_info const & error )
					{
						return handle_error(error);
					} );
			},
			[]( leaf::catch_<> )
			{
				return 3;
			},
			[]
			{
				return 4;
			} );

		BOOST_TEST_EQ(r, 3);
	}

	return boost::report_errors();
}