C：U64和uint64_t之间的差异(C: Difference between U64 and uint64_t)

 我在使用Java几年后尝试学习C语言。 我发现了一些我想要重现的代码，看起来像这样： 
 
U64 attack_table[...]; // ~840 KiB 

struct SMagic {
   U64* ptr;  // pointer to attack_table for each particular square
   U64 mask;  // to mask relevant squares of both lines (no outer squares)
   U64 magic; // magic 64-bit factor
   int shift; // shift right
};

SMagic mBishopTbl[64];
SMagic mRookTbl[64];

U64 bishopAttacks(U64 occ, enumSquare sq) {
   U64* aptr = mBishopTbl[sq].ptr;
   occ      &= mBishopTbl[sq].mask;
   occ      *= mBishopTbl[sq].magic;
   occ     >>= mBishopTbl[sq].shift;
   return aptr[occ]; 
}

U64 rookAttacks(U64 occ, enumSquare sq) {
   U64* aptr = mRookTbl[sq].ptr;
   occ      &= mRookTbl[sq].mask;
   occ      *= mRookTbl[sq].magic;
   occ     >>= mRookTbl[sq].shift;
   return aptr[occ];
}
 
 代码并不重要，但我已经失败了使用相同的数据类型： U64 ，我只找到了uint64_t 。 现在我想知道U64 ， uint64_t和long的区别在哪里。 
 
 如果有人可以向我简要解释一下，包括每个人的优势，我感到非常高兴。 
 
 问候，芬兰人 

I am trying to learn C after working with Java for a couple of years. I've found some code that I wanted to reproduce which looked something like this:
 
U64 attack_table[...]; // ~840 KiB 

struct SMagic {
   U64* ptr;  // pointer to attack_table for each particular square
   U64 mask;  // to mask relevant squares of both lines (no outer squares)
   U64 magic; // magic 64-bit factor
   int shift; // shift right
};

SMagic mBishopTbl[64];
SMagic mRookTbl[64];

U64 bishopAttacks(U64 occ, enumSquare sq) {
   U64* aptr = mBishopTbl[sq].ptr;
   occ      &= mBishopTbl[sq].mask;
   occ      *= mBishopTbl[sq].magic;
   occ     >>= mBishopTbl[sq].shift;
   return aptr[occ]; 
}

U64 rookAttacks(U64 occ, enumSquare sq) {
   U64* aptr = mRookTbl[sq].ptr;
   occ      &= mRookTbl[sq].mask;
   occ      *= mRookTbl[sq].magic;
   occ     >>= mRookTbl[sq].shift;
   return aptr[occ];
}
 
The code is not that important but I already failed at using the same datatype: U64, I only found uint64_t. Now I would like to know where the difference in U64, uint64_t and long is.
 
I am very happy if someone could briefly explain this one to me, including the advantage of each of them.
 
Greetings, Finn

原文：https://stackoverflow.com/questions/50556046