diff options
Diffstat (limited to 'boost/container/string.hpp')
| -rw-r--r-- | boost/container/string.hpp | 185 |
1 files changed, 115 insertions, 70 deletions
diff --git a/boost/container/string.hpp b/boost/container/string.hpp index 6c0cc96870..ca51cfdd73 100644 --- a/boost/container/string.hpp +++ b/boost/container/string.hpp @@ -98,27 +98,25 @@ class basic_string_base basic_string_base() : members_() - { init(); } + {} explicit basic_string_base(const allocator_type& a) : members_(a) - { init(); } + {} explicit basic_string_base(BOOST_RV_REF(allocator_type) a) : members_(boost::move(a)) - { this->init(); } + {} basic_string_base(const allocator_type& a, size_type n) : members_(a) { - this->init(); this->allocate_initial_block(n); } explicit basic_string_base(size_type n) : members_() { - this->init(); this->allocate_initial_block(n); } @@ -140,6 +138,11 @@ class basic_string_base pointer start; long_t() + : is_short(0) + {} + + long_t(size_type len, size_type stor, pointer ptr) + : is_short(0), length(len), storage(stor), start(ptr) {} long_t(const long_t &other) @@ -190,35 +193,49 @@ class basic_string_base value_type data[UnalignedFinalInternalBufferChars]; }; - union repr_t + union repr_t_size_t { long_raw_t r; short_t s; + }; - const short_t &short_repr() const - { return s; } - - const long_t &long_repr() const - { return *static_cast<const long_t*>(static_cast<const void*>(r.data)); } - - short_t &short_repr() - { return s; } - - long_t &long_repr() - { return *static_cast<long_t*>(static_cast<void*>(&r)); } + union repr_t + { + long_raw_t r_aligner; + short_t s_aligner; + unsigned char data[sizeof(repr_t_size_t)]; }; struct members_holder : public Allocator { + void init() + { + short_t &s = *::new(this->m_repr.data) short_t; + s.h.is_short = 1; + s.h.length = 0; + } + members_holder() : Allocator() - {} + { this->init(); } template<class AllocatorConvertible> explicit members_holder(BOOST_FWD_REF(AllocatorConvertible) a) : Allocator(boost::forward<AllocatorConvertible>(a)) - {} + { this->init(); } + + const short_t *pshort_repr() const + { return reinterpret_cast<const short_t*>(m_repr.data); } + + const long_t *plong_repr() const + { return reinterpret_cast<const long_t*>(m_repr.data); } + + short_t *pshort_repr() + { return reinterpret_cast<short_t*>(m_repr.data); } + + long_t *plong_repr() + { return reinterpret_cast<long_t*>(m_repr.data); } repr_t m_repr; } members_; @@ -246,32 +263,51 @@ class basic_string_base return hdr.is_short != 0; } - void is_short(bool yes) + short_t *construct_short() { - const bool was_short = this->is_short(); - if(yes && !was_short){ - allocator_traits_type::destroy - ( this->alloc() - , static_cast<long_t*>(static_cast<void*>(&this->members_.m_repr.r)) - ); - this->members_.m_repr.s.h.is_short = true; - } - else if(!yes && was_short){ - allocator_traits_type::construct - ( this->alloc() - , static_cast<long_t*>(static_cast<void*>(&this->members_.m_repr.r)) - ); - this->members_.m_repr.s.h.is_short = false; + short_t *ps = ::new(this->members_.m_repr.data) short_t; + ps->h.is_short = 1; + return ps; + } + + void destroy_short() + { + BOOST_ASSERT(this->is_short()); + this->members_.pshort_repr()->~short_t(); + } + + short_t *assure_short() + { + if (!this->is_short()){ + this->destroy_long(); + return construct_short(); } + return this->members_.pshort_repr(); } - private: - void init() + long_t *construct_long() + { + long_t *pl = ::new(this->members_.m_repr.data) long_t; + //is_short flag is written in the constructor + return pl; + } + + void destroy_long() + { + BOOST_ASSERT(!this->is_short()); + this->members_.plong_repr()->~long_t(); + } + + long_t *assure_long() { - this->members_.m_repr.s.h.is_short = 1; - this->members_.m_repr.s.h.length = 0; + if (this->is_short()){ + this->destroy_short(); + return this->construct_long(); + } + return this->members_.plong_repr(); } + protected: typedef dtl::integral_constant<unsigned, @@ -334,7 +370,8 @@ class basic_string_base size_type new_cap = this->next_capacity(n); pointer reuse = 0; pointer p = this->allocation_command(allocate_new, n, new_cap, reuse); - this->is_short(false); + BOOST_ASSERT(this->is_short()); + this->construct_long(); this->priv_long_addr(p); this->priv_long_size(0); this->priv_storage(new_cap); @@ -356,10 +393,16 @@ class basic_string_base { return this->priv_storage() - 1; } pointer priv_short_addr() const - { return pointer_traits::pointer_to(const_cast<value_type&>(this->members_.m_repr.short_repr().data[0])); } + { return pointer_traits::pointer_to(const_cast<value_type&>(this->members_.pshort_repr()->data[0])); } + + //GCC seems a bit confused about uninitialized accesses + #if defined(BOOST_GCC) && (BOOST_GCC >= 40700) + #pragma GCC diagnostic push + #pragma GCC diagnostic ignored "-Wmaybe-uninitialized" + #endif pointer priv_long_addr() const - { return this->members_.m_repr.long_repr().start; } + { return this->members_.plong_repr()->start; } pointer priv_addr() const { @@ -378,7 +421,7 @@ class basic_string_base } void priv_long_addr(pointer addr) - { this->members_.m_repr.long_repr().start = addr; } + { this->members_.plong_repr()->start = addr; } size_type priv_storage() const { return this->is_short() ? priv_short_storage() : priv_long_storage(); } @@ -387,7 +430,7 @@ class basic_string_base { return InternalBufferChars; } size_type priv_long_storage() const - { return this->members_.m_repr.long_repr().storage; } + { return this->members_.plong_repr()->storage; } void priv_storage(size_type storage) { @@ -397,17 +440,17 @@ class basic_string_base void priv_long_storage(size_type storage) { - this->members_.m_repr.long_repr().storage = storage; + this->members_.plong_repr()->storage = storage; } size_type priv_size() const { return this->is_short() ? this->priv_short_size() : this->priv_long_size(); } size_type priv_short_size() const - { return this->members_.m_repr.short_repr().h.length; } + { return this->members_.pshort_repr()->h.length; } size_type priv_long_size() const - { return this->members_.m_repr.long_repr().length; } + { return this->members_.plong_repr()->length; } void priv_size(size_type sz) { @@ -418,14 +461,14 @@ class basic_string_base } void priv_short_size(size_type sz) - { - this->members_.m_repr.s.h.length = (unsigned char)sz; - } + { this->members_.pshort_repr()->h.length = (unsigned char)sz; } void priv_long_size(size_type sz) - { - this->members_.m_repr.long_repr().length = sz; - } + { this->members_.plong_repr()->length = sz; } + + #if defined(BOOST_GCC) && (BOOST_GCC >= 40700) + #pragma GCC diagnostic pop + #endif void swap_data(basic_string_base& other) { @@ -436,23 +479,23 @@ class basic_string_base other.members_.m_repr = tmp; } else{ - short_t short_backup(this->members_.m_repr.short_repr()); - this->members_.m_repr.short_repr().~short_t(); - ::new(&this->members_.m_repr.long_repr()) long_t(other.members_.m_repr.long_repr()); - other.members_.m_repr.long_repr().~long_t(); - ::new(&other.members_.m_repr.short_repr()) short_t(short_backup); + short_t short_backup(*this->members_.pshort_repr()); + this->members_.pshort_repr()->~short_t(); + ::new(this->members_.plong_repr()) long_t(*other.members_.plong_repr()); + other.members_.plong_repr()->~long_t(); + ::new(other.members_.pshort_repr()) short_t(short_backup); } } else{ if(other.is_short()){ - short_t short_backup(other.members_.m_repr.short_repr()); - other.members_.m_repr.short_repr().~short_t(); - ::new(&other.members_.m_repr.long_repr()) long_t(this->members_.m_repr.long_repr()); - this->members_.m_repr.long_repr().~long_t(); - ::new(&this->members_.m_repr.short_repr()) short_t(short_backup); + short_t short_backup(*other.members_.pshort_repr()); + other.members_.pshort_repr()->~short_t(); + ::new(other.members_.plong_repr()) long_t(*this->members_.plong_repr()); + this->members_.plong_repr()->~long_t(); + ::new(this->members_.pshort_repr()) short_t(short_backup); } else{ - boost::adl_move_swap(this->members_.m_repr.long_repr(), other.members_.m_repr.long_repr()); + boost::adl_move_swap(*this->members_.plong_repr(), *other.members_.plong_repr()); } } } @@ -830,7 +873,7 @@ class basic_string if(flag && this_alloc != x_alloc){ if(!this->is_short()){ this->deallocate_block(); - this->is_short(true); + this->assure_short(); Traits::assign(*this->priv_addr(), CharT(0)); this->priv_short_size(0); } @@ -853,7 +896,7 @@ class basic_string BOOST_NOEXCEPT_IF(allocator_traits_type::propagate_on_container_move_assignment::value || allocator_traits_type::is_always_equal::value) { - //for move constructor, no aliasing (&x != this) is assummed. + //for move constructor, no aliasing (&x != this) is assumed. BOOST_ASSERT(this != &x); allocator_type &this_alloc = this->alloc(); allocator_type &x_alloc = x.alloc(); @@ -1159,7 +1202,9 @@ class basic_string Traits::copy( boost::movelib::to_raw_pointer(this->priv_short_addr()) , boost::movelib::to_raw_pointer(long_addr) , long_size+1); - this->is_short(true); + BOOST_ASSERT(!this->is_short()); + this->destroy_long(); + this->construct_short(); this->alloc().deallocate(long_addr, long_storage); } else{ @@ -1763,7 +1808,7 @@ class basic_string this->priv_construct_null(new_start + new_length); this->deallocate_block(); - this->is_short(false); + this->assure_long(); this->priv_long_addr(new_start); this->priv_long_size(new_length); this->priv_long_storage(new_cap); @@ -1782,7 +1827,7 @@ class basic_string //Now initialize the new data priv_uninitialized_copy(first, last, new_start + before); this->priv_construct_null(new_start + (old_size + n)); - this->is_short(false); + this->assure_long(); this->priv_long_addr(new_start); this->priv_long_size(old_size + n); this->priv_long_storage(new_cap); @@ -2790,7 +2835,7 @@ class basic_string this->priv_construct_null(new_start + new_length); } this->deallocate_block(); - this->is_short(false); + this->assure_long(); this->priv_long_addr(new_start); this->priv_long_size(new_length); this->priv_storage(new_cap); @@ -2933,7 +2978,7 @@ class basic_string #endif //#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED }; -#if __cplusplus >= 201703L +#ifndef BOOST_CONTAINER_NO_CXX17_CTAD template <typename InputIterator> basic_string(InputIterator, InputIterator) -> |