Sprout/source/libs/string/char_traits/length.rst
2013-09-05 13:09:04 +09:00

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.. _sprout-string-char_traits-length:
###############################################################################
length
###############################################################################
Interface
========================================
.. sourcecode:: c++
static SPROUT_CONSTEXPR std::size_t length(char_type const* s);
Returns
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| Equivalent to ``std::char_traits<Char>::length(s)`` in constant expression.
Examples
========================================
.. sourcecode:: c++
#include <sprout/string.hpp>
using namespace sprout;
SPROUT_STATIC_CONSTEXPR char const* x = "homuhomu";
SPROUT_STATIC_CONSTEXPR auto result = char_traits<char>::length(x);
static_assert(result == 8, "length of x is 8.");
Complexity
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| linear.
| Recursive function invocations in *O(logN)* (logarithmic) depth.
Header
========================================
| ``sprout/string/char_traits.hpp``
| Convenience header: ``sprout/string.hpp``