diff options
Diffstat (limited to 'src/prevector.h')
| -rw-r--r-- | src/prevector.h | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/src/prevector.h b/src/prevector.h index 4fb07688ff..f2a0c3e05b 100644 --- a/src/prevector.h +++ b/src/prevector.h @@ -15,7 +15,6 @@ #include <type_traits> #include <utility> -#pragma pack(push, 1) /** Implements a drop-in replacement for std::vector<T> which stores up to N * elements directly (without heap allocation). The types Size and Diff are * used to store element counts, and can be any unsigned + signed type. @@ -147,14 +146,20 @@ public: }; private: - size_type _size = 0; +#pragma pack(push, 1) union direct_or_indirect { char direct[sizeof(T) * N]; struct { - size_type capacity; char* indirect; + size_type capacity; }; - } _union = {}; + }; +#pragma pack(pop) + alignas(char*) direct_or_indirect _union = {}; + size_type _size = 0; + + static_assert(alignof(char*) % alignof(size_type) == 0 && sizeof(char*) % alignof(size_type) == 0, "size_type cannot have more restrictive alignment requirement than pointer"); + static_assert(alignof(char*) % alignof(T) == 0, "value_type T cannot have more restrictive alignment requirement than pointer"); T* direct_ptr(difference_type pos) { return reinterpret_cast<T*>(_union.direct) + pos; } const T* direct_ptr(difference_type pos) const { return reinterpret_cast<const T*>(_union.direct) + pos; } @@ -523,6 +528,5 @@ public: return item_ptr(0); } }; -#pragma pack(pop) #endif // BITCOIN_PREVECTOR_H |