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What does @synchronized() do as a singleton method in objective C?
...ES NOT do the same as @syncrhonized, it can be a substitute ONLY under the allocation of a singleton.
– jugutier
Aug 22 '16 at 21:32
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Why can't C compilers rearrange struct members to eliminate alignment padding? [duplicate]
...and is much less time consuming than other compiler tasks such as register allocation, function inlining, constant folding, transformation of a switch statement into binary search, etc. Thus the benefits to be gained by allowing the compiler to optimize data structures appear to be less tangible tha...
How can I propagate exceptions between threads?
...;
try {
std::rethrow_exception(e);
} catch (const std::bad_alloc&) {
puts("Success!");
}
}
I have no idea what I was doing wrong in 2013, but I'm sure it was my fault.]
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Initializing a struct to 0
...so just declare it myStruct _m;
If the data is a local variable or a heap-allocated zone, clear it with memset like:
memset(&m, 0, sizeof(myStruct));
Current compilers (e.g. recent versions of gcc) optimize that quite well in practice. This works only if all zero values (include null pointer...
How to check if running in Cygwin, Mac or Linux?
...LAGS += -DNDEBUG
endif
ifeq ($(uname_S),GNU/kFreeBSD)
CFLAGS += -D_BSD_ALLOC
endif
ifeq ($(uname_S),UnixWare)
CFLAGS += -Wextra
endif
...
See also this complete answer about uname -s and Makefile.
The correspondence table in the bottom of this answer is from Wikipedia article about uname. P...
Why are Where and Select outperforming just Select?
...reating a LINQ expression is cheap. Calling delegate functions is cheap. Allocating and looping over an iterator is cheap. But it's even cheaper to not do these things. Thus, if you find that a LINQ statement is the bottleneck in your program, in my experience rewriting it without LINQ will alwa...
smart pointers (boost) explained
...neither transferable nor sharable. It's just usable if you locally need to allocate memory, but be sure it's freed again when it goes out of scope. But it can still be swapped with another scoped_ptr, if you wish to do so.
shared_ptr is a smart pointer that shares ownership (third kind above). It ...
When should you use constexpr capability in C++11?
... @alecov Definitly not everything... I/O, syscall and dynamic memory allocation definitly cann't be marked as constexpr Besides, not everything should be constexpr.
– JiaHao Xu
Oct 8 '18 at 7:52
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What is the difference between tinyint, smallint, mediumint, bigint and int in MySQL?
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The difference is the amount of memory allocated to each integer, and how large a number they each can store.
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Summarizing multiple columns with dplyr? [duplicate]
...#> # A tibble: 3 x 6
#> expression min median `itr/sec` mem_alloc `gc/sec`
#> <bch:expr> <bch:tm> <bch:tm> <dbl> <bch:byt> <dbl>
#> 1 dplyr 2.81ms 2.85ms 328. NA 17.3
#> 2 purrrlyr 7.96ms 8.04ms ...