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Diffstat (limited to 'src/boost/libs/contract/example/features/overload.cpp')
| -rw-r--r-- | src/boost/libs/contract/example/features/overload.cpp | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/src/boost/libs/contract/example/features/overload.cpp b/src/boost/libs/contract/example/features/overload.cpp new file mode 100644 index 00000000..2feab347 --- /dev/null +++ b/src/boost/libs/contract/example/features/overload.cpp @@ -0,0 +1,202 @@ + +// Copyright (C) 2008-2018 Lorenzo Caminiti +// Distributed under the Boost Software License, Version 1.0 (see accompanying +// file LICENSE_1_0.txt or a copy at http://www.boost.org/LICENSE_1_0.txt). +// See: http://www.boost.org/doc/libs/release/libs/contract/doc/html/index.html + +#include <boost/contract.hpp> +#include <boost/optional.hpp> +#include <string> +#include <sstream> +#include <cassert> + +class lines { +public: + virtual std::string str(boost::contract::virtual_* v = 0) const = 0; + virtual std::string& str(boost::contract::virtual_* v = 0) = 0; + + virtual void put(std::string const& x, + boost::contract::virtual_* v = 0) = 0; + + virtual void put(char x, boost::contract::virtual_* v = 0) = 0; + + virtual void put(int x, bool tab = false, + boost::contract::virtual_* v = 0) = 0; +}; + +std::string lines::str(boost::contract::virtual_* v) const { + std::string result; + boost::contract::check c = boost::contract::public_function(v, result, this) + .postcondition([&] (std::string const& result) { + if(result != "") BOOST_CONTRACT_ASSERT(*result.rbegin() == '\n'); + }) + ; + assert(false); + return result; +} + +std::string& lines::str(boost::contract::virtual_* v) { + boost::optional<std::string&> result; + boost::contract::check c = boost::contract::public_function(v, result, this) + .postcondition([&] (boost::optional<std::string const&> const& result) { + if(*result != "") BOOST_CONTRACT_ASSERT(*result->rbegin() == '\n'); + }) + ; + assert(false); + return *result; +} + +void lines::put(std::string const& x, boost::contract::virtual_* v) { + boost::contract::check c = boost::contract::public_function(v, this) + .precondition([&] { + BOOST_CONTRACT_ASSERT(*x.rbegin() != '\n'); + }) + ; + assert(false); +} + +void lines::put(char x, boost::contract::virtual_* v) { + boost::contract::check c = boost::contract::public_function(v, this) + .precondition([&] { + BOOST_CONTRACT_ASSERT(x != '\n'); + }) + ; + assert(false); +} + +void lines::put(int x, bool tab, + boost::contract::virtual_* v) { + boost::contract::check c = boost::contract::public_function(v, this) + .precondition([&] { + BOOST_CONTRACT_ASSERT(x >= 0); + }) + ; + assert(false); +} + +//[overload +class string_lines + #define BASES public lines + : BASES +{ +public: + typedef BOOST_CONTRACT_BASE_TYPES(BASES) base_types; + #undef BASES + + BOOST_CONTRACT_OVERRIDES(str) // Invoked only once for all `str` overloads. + + std::string str(boost::contract::virtual_* v = 0) const /* override */ { + std::string result; + boost::contract::check c = boost::contract::public_function< + override_str>( + v, result, + // `static_cast` resolves overloaded function pointer ambiguities. + static_cast<std::string (string_lines::*)( + boost::contract::virtual_*) const>(&string_lines::str), + this + ); + + return result = str_; + } + + // Overload on (absence of) `const` qualifier. + std::string& str(boost::contract::virtual_* v = 0) /* override */ { + boost::contract::check c = boost::contract::public_function< + override_str>( + v, str_, + // `static_cast` resolves overloaded function pointer ambiguities. + static_cast<std::string& (string_lines::*)( + boost::contract::virtual_*)>(&string_lines::str), + this + ); + + return str_; + } + + BOOST_CONTRACT_OVERRIDES(put) // Invoked only once for all `put` overloads. + + void put(std::string const& x, + boost::contract::virtual_* v = 0) /* override */ { + boost::contract::old_ptr<std::string> old_str = + BOOST_CONTRACT_OLDOF(v, str()); + boost::contract::check c = boost::contract::public_function< + override_put>( + v, + // `static_cast` resolves overloaded function pointer ambiguities. + static_cast<void (string_lines::*)(std::string const&, + boost::contract::virtual_*)>(&string_lines::put), + this, x + ) + .postcondition([&] { + BOOST_CONTRACT_ASSERT(str() == *old_str + x + '\n'); + }) + ; + + str_ = str_ + x + '\n'; + } + + // Overload on argument type. + void put(char x, boost::contract::virtual_* v = 0) /* override */ { + boost::contract::old_ptr<std::string> old_str = + BOOST_CONTRACT_OLDOF(v, str()); + boost::contract::check c = boost::contract::public_function< + override_put>( + v, + // `static_cast` resolves overloaded function pointer ambiguities. + static_cast<void (string_lines::*)(char, + boost::contract::virtual_*)>(&string_lines::put), + this, x + ) + .postcondition([&] { + BOOST_CONTRACT_ASSERT(str() == *old_str + x + '\n'); + }) + ; + + str_ = str_ + x + '\n'; + } + + // Overload on argument type and arity (also with default parameter). + void put(int x, bool tab = false, + boost::contract::virtual_* v = 0) /* override */ { + boost::contract::old_ptr<std::string> old_str = + BOOST_CONTRACT_OLDOF(v, str()); + boost::contract::check c = boost::contract::public_function< + override_put>( + v, + // `static_cast` resolves overloaded function pointer ambiguities. + static_cast<void (string_lines::*)(int, bool, + boost::contract::virtual_*)>(&string_lines::put), + this, x, tab + ) + .postcondition([&] { + std::ostringstream s; + s << x; + BOOST_CONTRACT_ASSERT( + str() == *old_str + (tab ? "\t" : "") + s.str() + '\n'); + }) + ; + + std::ostringstream s; + s << str_ << (tab ? "\t" : "") << x << '\n'; + str_ = s.str(); + } + +private: + std::string str_; +}; +//] + +int main() { + string_lines s; + s.put("abc"); + assert(s.str() == "abc\n"); + s.put('x'); + assert(s.str() == "abc\nx\n"); + s.put(10); + assert(s.str() == "abc\nx\n10\n"); + s.put(20, true); + lines const& l = s; + assert(l.str() == "abc\nx\n10\n\t20\n"); + return 0; +} + |