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Android Studio Signed APK Not Installing

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I am in Android Studio and signing an APK under Build > Generate Signed APK and using the wizard. Everything appears to sign fine and an .apk file is generated. When I go copy this file over to my device (either Nexus 7 or Moto X) it won't install. I get an "install failed" message. I can't figure out what's going wrong at all. I have put this .apk up in the google play developer console under "alpha testing" and it was accepted fine (I'm waiting for the tester link to become active to try and download / install from there). The instructions for the wizard here ( http://developer.android.com

Is there some meaningful statistical data to justify keeping signed integer arithmetic overflow undefined?

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The C Standard explicitly specifies signed integer overflow as having undefined behavior . Yet most CPUs implement signed arithmetics with defined semantics for overflow (except maybe for division overflow: x / 0 and INT_MIN / -1 ). Compilers writers have been taking advantage of the undefinedness of such overflows to add more aggressive optimisations that tend to break legacy code in very subtle ways. For example this code may have worked on older compilers but does not anymore on current versions of gcc and clang : /* Tncrement a by a value in 0..255, clamp a to positive integers. The code

What does it mean for a char to be signed?

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Given that signed and unsigned ints use the same registers, etc., and just interpret bit patterns differently, and C chars are basically just 8-bit ints, what's the difference between signed and unsigned chars in C? I understand that the signedness of char is implementation defined, and I simply can't understand how it could ever make a difference, at least when char is used to hold strings instead of to do math. It won't make a difference for strings. But in C you can use a char to do math, when it will make a difference. In fact, when working in constrained memory environments, like embedded

In C Left shift (char) 0xFF by 8 and cast it to int

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问题 On left shift of (char) 0xff by 8 and casting it to int we get -256 or 0xffffff00. Can somebody explain why this should happen? #include <stdio.h> int main (void) { char c = 0xff; printf("%d %x\n", (int)(c<<8),(int)(c<<8)); return 0; } Output is -256 ffffff00 回答1: char can be signed or unsigned - it's implementation-defined. You see these results because char is signed by default on your compiler. For the signed char 0xFF corresponds to −1 (that's how two's complement work). When you try to

Why is (18446744073709551615 == -1) true?

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问题 When I was working on string::npos I noticed something and I couldn't find any explanation for it on the web. (string::npos == ULONG_MAX) and (string::npos == -1) are true. So I tried this: (18446744073709551615 == -1) which is also true. How can it be possible? Is it because of binary conversation? 回答1: 18,446,744,073,709,551,615 This number mentioned, 18,446,744,073,709,551,615 , is actually 2^64 − 1 . The important thing here is that 2^64-1 is essentially 0-based 2^64 . The first digit of

In C, why is “signed int” faster than “unsigned int”?

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In C, why is signed int faster than unsigned int ? True, I know that this has been asked and answered multiple times on this website (links below). However, most people said that there is no difference. I have written code and accidentally found a significant performance difference. Why would the "unsigned" version of my code be slower than the "signed" version (even when testing the same number)? (I have a x86-64 Intel processor). Similar links Faster comparing signed than unsigned ints performance of unsigned vs signed integers Compile Command: gcc -Wall -Wextra -pedantic -O3 -Wl,-O3 -g0

Signed 64 by 32 integer division

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问题 Assuming you have a machine instruction udive that does a special case 64 by 32 unsigned division by taking a (32bit dividend << 32) / 32bit divisor, we can do a full 64 by 32 division using the following: // assume: a / b guaranteed not to overflow a = 64bit dividend, a.h & a.l are hi & lo 32bits respectively b = 32bit divisor q1 = udive(a.h, b) // (a.h << 32) / b r1 = -(q1 * b) // remainder of the above, shortcut since a.h & 0xffffffff == 0 q2 = a.l / b // a.l / b using regular unsigned

What is the difference between “int” and “uint” / “long” and “ulong”?

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I know about int and long (32-bit and 64-bit numbers), but what are uint and ulong ? Isak Savo 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: int: –2147483648 to 2147483647 uint: 0 to 4294967295 And for long (64 bit): long: -9223372036854775808 to 9223372036854775807 ulong: 0 to 18446744073709551615 Mark Byers

What Are Integer Literal Type? And How They Are Stored?

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I have just started learning C and a question has bugged me for a while now. If I write int i = -1; unsigned int j = 2; unsigned int k = -2; What is the type of integer literal -1 and 2 and -2 , and how does it get converted to get stored in signed int and unsigned int ? What is meant by signed integer, is that the property of variable or integer literal too? Like -2 is signed integer and 2 is unsigned integer? First off, -1 is not an integer constant. It's an expression consisting of a unary - operator applied to the constant 1 . In C99 and C11, the type of a decimal integer constant is the

Can the Postgres data type NUMERIC store signed values?

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In PostgreSQL, I would like to store signed values -999.9 - 9999.9 . Can I use numeric(5.1) for this? Or what type should I use? Erwin Brandstetter You can certainly use the arbitrary precision type numeric with a precision of 5 and a scale of 1, just like @Simon commented , but without the syntax error. Use a comma( , ) instead of the dot ( . ) in the type modifier: SELECT numeric(5,1) '-999.9' AS nr_lower , numeric(5,1) '9999.9' AS nr_upper; nr_lower | nr_upper ----------+---------- -999.9 | 9999.9 The minus sign and the dot in the string literal do not count against the allowed maximum of