I had the same problem and I figured there wasn’t any helpful answer around on the internet so hoping this should help everyone in the future. When using GoogleMaps for Android, you need two keys – debug and release. The “debug” key is kind of a misleading term. This key is also to be used … Read more
It’s all in your things.size() type. It isn’t int, but size_t (it exists in C++, not in C) which equals to some “usual” unsigned type, i.e. unsigned int for x86_32. Operator “less” (<) cannot be applied to two operands of different sign. There’s just no such opcodes, and standard doesn’t specify, whether compiler can make … Read more
For the official answer – Section 4.7 conv.integral “If the destination type is unsigned, the resulting value is the least unsigned integer congruent to the source integer (modulo 2n where n is the number of bits used to represent the unsigned type). [ Note: In a two’s complement representation, this conversion is conceptual and there … Read more
No, your 2nd code isn’t correct, but you are close: if you set int half = INT_MAX/2; int half1 = half + 1; the result of an addition is INT_MAX. (INT_MAX is always an odd number). So this is valid input. But in your routine you will have INT_MAX – half == half1 and you … Read more
When comparing signed with unsigned, the compiler converts the signed value to unsigned. For equality, this doesn’t matter, -1 == (unsigned) -1. For other comparisons it matters, e.g. the following is true: -1 > 2U. EDIT: References: 5/9: (Expressions) Many binary operators that expect operands of arithmetic or enumeration type cause conversions and yield result … Read more
Assuming: You have 2’s-complement representations in mind; and, By (unsigned long) you mean unsigned 32-bit integer, then you just need to add 2**32 (or 1 << 32) to the negative value. For example, apply this to -1: >>> -1 -1 >>> _ + 2**32 4294967295L >>> bin(_) ‘0b11111111111111111111111111111111’ Assumption #1 means you want -1 to … Read more
ssize_t is used for functions whose return value could either be a valid size, or a negative value to indicate an error. It is guaranteed to be able to store values at least in the range [-1, SSIZE_MAX] (SSIZE_MAX is system-dependent). So you should use size_t whenever you mean to return a size in bytes, … Read more
The rationale is described in this paper. A quote: When span was adopted into C++17, it used a signed integer both as an index and a size. Partly this was to allow for the use of “-1” as a sentinel value to indicate a type whose size was not known at compile time. But having … Read more
The primitive data types prefixed with “u” are unsigned versions with the same bit sizes. Effectively, this means they cannot store negative numbers, but on the other hand they can store positive numbers twice as large as their signed counterparts. The signed counterparts do not have “u” prefixed. The limits for int (32 bit) are: … Read more
use std::stringstream unsigned int x; std::stringstream ss; ss << std::hex << “fffefffe”; ss >> x; the following example produces -65538 as its result: #include <sstream> #include <iostream> int main() { unsigned int x; std::stringstream ss; ss << std::hex << “fffefffe”; ss >> x; // output it as a signed type std::cout << static_cast<int>(x) << std::endl; … Read more