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91 lines
3.4 KiB
C++
91 lines
3.4 KiB
C++
//////////////////////////////////////////////////////////////////////////////
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//
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// (C) Copyright Ion Gaztanaga 2013-2013. Distributed under the Boost
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// Software License, Version 1.0. (See accompanying file
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// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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// See http://www.boost.org/libs/container for documentation.
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//
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//////////////////////////////////////////////////////////////////////////////
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//[doc_custom_string
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#include <boost/container/string.hpp>
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//Make sure assertions are active
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#ifdef NDEBUG
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#undef NDEBUG
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#endif
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#include <cassert>
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int main ()
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{
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using namespace boost::container;
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//--------------------------
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// Option "stored_size"
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//--------------------------
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//This option specifies that a string that will use "unsigned char" as
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//the type to store capacity or size internally.
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typedef string_options< stored_size<unsigned char> >::type size_option_t;
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//Size-optimized string is smaller than the default one.
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typedef basic_string<char, std::char_traits<char>, void, size_option_t > size_optimized_string_t;
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assert(( sizeof(size_optimized_string_t) < sizeof(basic_string<char>) ));
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//The internal small string optimization buffer is also smaller
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assert(( size_optimized_string_t().capacity() < basic_string<char>().capacity() ));
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//Requesting capacity for more elements than representable by half of the
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//"unsigned char" max (due to the need to a bit to indicate short/long representation)
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//minus 1 (due to the terminating null) is an error in the size optimized string.
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bool exception_thrown = false;
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/*<-*/
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#ifndef BOOST_NO_EXCEPTIONS
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BOOST_CONTAINER_TRY{ size_optimized_string_t v(127, 'a');} BOOST_CONTAINER_CATCH(...) { exception_thrown = true; } BOOST_CONTAINER_CATCH_END
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#else
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exception_thrown = true;
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#endif //BOOST_NO_EXCEPTIONS
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/*->*/
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//=try { size_optimized_string_t v(127, 'a'); }
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//=catch(...){ exception_thrown = true; }
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assert(exception_thrown == true);
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//--------------------------
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// Option "inline_chars"
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//--------------------------
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//This option specifies the capacity of the internally stored buffer
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//The maximum value due to internal data organization is 127 chars
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typedef string_options< inline_chars<100> >::type inline_chars_option_t;
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typedef basic_string<char, std::char_traits<char>, void, inline_chars_option_t > inline100_string_t;
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//The size of the object will grow accordingly
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assert(( sizeof(inline100_string_t) > sizeof(basic_string<char>) ));
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assert(( sizeof(inline100_string_t) > 100 ));
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//Internal capacity will be at least the specified one
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assert((inline100_string_t().capacity() >= 100));
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//--------------------------
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// Option "growth_factor"
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//--------------------------
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//This option specifies that a string will increase its capacity 50%
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//each time the previous capacity was exhausted.
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typedef string_options< growth_factor<growth_factor_50> >::type growth_50_option_t;
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//Fill the string until full capacity is reached
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basic_string<char, std::char_traits<char>, void, growth_50_option_t > growth_50_string(5, 0);
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const std::size_t old_cap = growth_50_string.capacity();
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growth_50_string.resize(old_cap);
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//Now insert an additional item and check the new buffer is aproximately
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//50% bigger (rounding due to the null terminator might round down)
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growth_50_string.push_back(1);
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assert(growth_50_string.capacity() == old_cap*3/2);
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return 0;
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}
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//]
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