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- // Copyright Antony Polukhin, 2013-2019.
- // Distributed under the Boost Software License, Version 1.0.
- // (See the accompanying file LICENSE_1_0.txt
- // or a copy at <http://www.boost.org/LICENSE_1_0.txt>.)
- #include <boost/config.hpp>
- #ifdef BOOST_MSVC
- # pragma warning(disable: 4512) // generic_stringize.cpp(37) : warning C4512: 'stringize_functor' : assignment operator could not be generated
- #endif
- //[lexical_cast_stringize
- /*`
- In this example we'll make a `stringize` method that accepts a sequence, converts
- each element of the sequence into string and appends that string to the result.
- Example is based on the example from the [@http://www.packtpub.com/boost-cplusplus-application-development-cookbook/book Boost C++ Application Development Cookbook]
- by Antony Polukhin, ISBN 9781849514880.
- Step 1: Making a functor that converts any type to a string and remembers result:
- */
- #include <boost/lexical_cast.hpp>
- struct stringize_functor {
- private:
- std::string& result;
- public:
- explicit stringize_functor(std::string& res)
- : result(res)
- {}
- template <class T>
- void operator()(const T& v) const {
- result += boost::lexical_cast<std::string>(v);
- }
- };
- //` Step 2: Applying `stringize_functor` to each element in sequence:
- #include <boost/fusion/include/for_each.hpp>
- template <class Sequence>
- std::string stringize(const Sequence& seq) {
- std::string result;
- boost::fusion::for_each(seq, stringize_functor(result));
- return result;
- }
- //` Step 3: Using the `stringize` with different types:
- #include <cassert>
- #include <boost/fusion/adapted/boost_tuple.hpp>
- #include <boost/fusion/adapted/std_pair.hpp>
- int main() {
- boost::tuple<char, int, char, int> decim('-', 10, 'e', 5);
- assert(stringize(decim) == "-10e5");
- std::pair<int, std::string> value_and_type(270, "Kelvin");
- assert(stringize(value_and_type) == "270Kelvin");
- }
- //] [/lexical_cast_stringize]
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