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What is the bit size of long on 64-bit Windows?
...16_t - 16-bit integers
int32_t - 32-bit integers
int64_t - 64-bit integers
uintptr_t - unsigned integers big enough to hold pointers
intmax_t - biggest size of integer on the platform (might be larger than int64_t)
You can then code your application using these types where it matters, and being ve...
How to write a large buffer into a binary file in C++, fast?
...thm>
#include <iostream>
#include <cassert>
std::vector<uint64_t> GenerateData(std::size_t bytes)
{
assert(bytes % sizeof(uint64_t) == 0);
std::vector<uint64_t> data(bytes / sizeof(uint64_t));
std::iota(data.begin(), data.end(), 0);
std::shuffle(data.begin...
How can I get a precise time, for example in milliseconds in Objective-C?
... code is a weird conversion - last line of the first example is "return * (uint64_t *) &elapsedNano;" why not just "return (uint64_t)elapsedNano" ?
– Tyler
Dec 29 '10 at 23:00
...
maximum value of int
...
in C99 you can also use UINT64_MAX and INT64_MAX
– Dmitry Vyal
Oct 2 '13 at 9:08
3
...
How much is the overhead of smart pointers compared to normal pointers in C++?
...#include <iostream>
#include <chrono>
#include <thread>
uint32_t n = 100000000;
void t_m(void){
auto a = (char*) malloc(n*sizeof(char));
for(uint32_t i=0; i<n; i++) a[i] = 'A';
}
void t_u(void){
auto a = std::unique_ptr<char[]>(new char[n]);
for(uint32_t ...
Hash and salt passwords in C#
...6, 128-bit salt, 256-bit subkey, 10000 iterations.
* Format: { 0x01, prf (UInt32), iter count (UInt32), salt length (UInt32), salt, subkey }
* (All UInt32s are stored big-endian.)
*/
public string HashPassword(string password)
{
var prf = KeyDerivationPrf.HMACSHA256;
var rng = RandomNumb...
How to TryParse for Enum value?
...ak;
//case TypeCode.Byte:
//case TypeCode.UInt16:
//case TypeCode.UInt32:
//case TypeCode.UInt64:
default:
tokenUl = Convert.ToUInt64(tokenValue, CultureInfo.InvariantCulture);
br...
How to enumerate an enum with String type?
...orOfOne(unsafeBitCast((), T.self)))
case 1: cast = { unsafeBitCast(UInt8(truncatingBitPattern: $0), T.self) }
case 2: cast = { unsafeBitCast(UInt16(truncatingBitPattern: $0), T.self) }
case 4: cast = { unsafeBitCast(UInt32(truncatingBitPattern: $0), T.self) }
case 8: ...
Why unsigned integer is not available in PostgreSQL?
...additional constraint.
For an concrete example you could use
CREATE DOMAIN uint2 AS int4
CHECK(VALUE >= 0 AND VALUE < 65536);
Here is what psql gives when I try to abuse the type.
DS1=# select (346346 :: uint2);
ERROR: value for domain uint2 violates check constraint "uint2_check"
...
C++ Lock-free Hazard Pointer（冒险指针） - C/C++ - 清泛网 - 专注C/C++及内核技术
... this;
}
}
private:
std::unique_ptr<T> ptr_;
std::atomic_uint32_t cnt_;
};
仔细观察可以发现：
每一次的读取操作对应引用计数中增加的数值 1；
当所有的读取操作都完成时引用计数归 0，此时内存可以安全回收。
总结起来...