c++ - std::string and data alignment -


i'm planning use std::string generic data buffer (instead of roll own). need pack kinds of pod it, including user defined structs, memory buffer allocated std::string aligned such purpose ?

if it's unspecified in c++ standard, what's situation in libstdc++ ?

the host cpu x86_64.

first of all, std::string not best container use if want store arbitrary data. i'd suggest using std::vector instead.

second, alignment of allocations made container controlled allocator (the second template parameter, defaults std::allocator<t>). default allocator align allocations on size of largest standard type, long long or long double, respectively 8 , 16 bytes on machine, size of these types not mandated standard.

if want specific alignment should either check compiler aligns on, or ask alignment explicitly, supplying own allocator or using std::aligned_storage.


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