如何指定在VS2008一个64位无符号整型常量0x8000000000000000？ [英] How do you specify a 64 bit unsigned int const 0x8000000000000000 in VS2008?

问题描述

我看了一下微软特定后缀为I64整型常量。我想做一个无符号转变为ULONGLONG。结果
ULONGLONG bigNum64 =​​ 0x800000000000000i64＆GT;＆GT;设为myVal;

I read about the Microsoft specific suffix "i64" for integer constants. I want to do an UNsigned shift to a ULONGLONG.
ULONGLONG bigNum64 = 0x800000000000000i64 >> myval;

在普通的C，我会使用后缀U，例如类似的32位操作会结果
ULONG bigNum32 = 0x80000000U＆GT;＆GT;设为myVal;

In normal C, I would use the suffix "U", e.g. the similar 32 bit operation would be
ULONG bigNum32 = 0x80000000U >> myval;

我不希望2的补符号扩展到通过高位传播完成。我想在一个64位的常量数量UNS​​IGNED转变。我想我的第一次发言是要做一个有符号右移。

I do NOT want the 2's complement sign extension to propogate through the high bits. I want an UNSIGNED shift on a 64 bit const number. I think my first statement is going to do a SIGNED shift right.

我试过 0x800000000000000i64U 和 0x800000000000000u64 但得到编译器错误。

I tried 0x800000000000000i64U and 0x800000000000000u64 but got compiler errors.

推荐答案

您可以使用后缀 ULL ，这是标准的（C99和C ++ 0x中）的方式指定一个无符号长长整数文字和<$​​ C $ C>长长至少为64位。

You can use the suffix ull, which is the standard (C99 and C++0x) way to specify an unsigned long long integer literal, and a long long is at least 64 bits.

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