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Improve string allocation #92652

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e4fc044
Improve string allocation
MBkkt May 18, 2024
d05b553
Fix compilation
MBkkt May 18, 2024
4651e1c
Fix compilation
MBkkt May 18, 2024
757d827
Fix shrink_to_fit
MBkkt May 18, 2024
3dfea5c
Merge branch 'main' into patch-1
MBkkt Oct 28, 2024
1d9e567
Merge branch 'main' into patch-1
MBkkt May 22, 2025
80f6b05
Update string
MBkkt May 22, 2025
64ad928
Fix code format
MBkkt May 24, 2025
15850fa
Merge branch 'main' into patch-1
MBkkt Jun 14, 2025
eb8c0fd
Merge branch 'main' into patch-1
MBkkt Aug 13, 2025
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11 changes: 4 additions & 7 deletions libcxx/include/string
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Original file line number Diff line number Diff line change
Expand Up @@ -2292,14 +2292,9 @@ private:
}
enum { __alignment = 8 };
static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type __recommend(size_type __s) _NOEXCEPT {
if (__s < __min_cap) {
return static_cast<size_type>(__min_cap) - 1;
}
_LIBCPP_ASSERT_INTERNAL(__s >= __min_cap, "recommend is called for small string capacity");
const size_type __boundary = sizeof(value_type) < __alignment ? __alignment / sizeof(value_type) : __endian_factor;
size_type __guess = __align_it<__boundary>(__s + 1) - 1;
if (__guess == __min_cap)
__guess += __endian_factor;

_LIBCPP_ASSERT_INTERNAL(__guess >= __s, "recommendation is below the requested size");
return __guess;
}
Expand Down Expand Up @@ -3435,7 +3430,9 @@ _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::re

template <class _CharT, class _Traits, class _Allocator>
inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::shrink_to_fit() _NOEXCEPT {
size_type __target_capacity = __recommend(size());
size_type __target_capacity = size();
__target_capacity =
__target_capacity < __min_cap ? static_cast<size_type>(__min_cap) - 1 : __recommend(__target_capacity);
if (__target_capacity == capacity())
return;

Expand Down