How to use bit field with Swift to store values with more than 1 bit
Swift simply does not support bit fields, so you can only use the next larger integer type instead (in your case Int8) and accept that the variables need more memory, or use bit operations to access the different parts of the integer. For the second case you could define custom...
Declaring and using a bit field enum in Swift
You can build a struct that conforms to the RawOptionSet protocol, and you'll be able to use it like the built-in enum type but with bitmask functionality as well. The answer here shows how: Swift NS_OPTIONS-style bitmask enumerations.
Bit-field: Understanding how the following program works
We need to be very careful while using bit-fields. As you declared variable as only int, in C it is default signed int. If you see binary value of 13, it is 1101. So MSB is taken as sign value so you are getting -3. If you want it to...
How to marshal C++ struct containing DWORD bitfields in C#
c#,c,struct,marshalling,bit-fields
There's only ONE 32-bit integer in that entire structure. All the various components are packed into different subsets of the 32-bit structure. You'll probably want to use exactly one UInt32 field on the .NET side, and properties for access to the individual components. The .NET BitVector32 class can help you...
Gcc: Accessing and initializing unions and bitfields within struct
c,gcc,struct,unions,bit-fields
This can work. I think that the trick is name of structs and union. typedef union { int *client; void (*handler)(int sig, int par); }union_t; typedef struct { uint8_t presence:2; uint8_t is_hsm:1; uint8_t is_handler:1; }struct_t; typedef struct router_client { union_t test; uint8_t level; struct_t test2 } router_client_t; void main() {...
C++ (Somehow) limit struct to parent union size
You could make a specialization of the struct for different cases of C: template <int C = 3, typename T = unsigned char> union Color; template <typename T> union Color<3,T> { T v[3]; struct { T r,g,b; }; }; template <typename T> union Color<4,T> { T v[4]; struct { T...
bit field declaration in a c++ struct
You asked; I dont understand the significance of using two bit fields for c i.e, c:11,:0,. can anybody clear my vision about this? c is not defined using two bit-fields. The second one is an unnamed bit-field. Unnamed bit-fields with width of zero have special significance. This is what the...
A bit field of enumeration type and a value stored to it
It is a two's complement issue with signed values. You're going out of range of what a 5-bit signed value can represent. If you only have 5 bits to store the value of 16, you'll have 10000. The leading 1 indicates that this is a negative value. Only 4 bits...
Bitfields in C - aligning vs initializing [on hold]
Your first example does not denote a bit field. This would be a struct instead of an enum. In newer C++ you can define default values to struct members: typedef struct { unsigned int x = 1 << 0; /* Default value 1 << 0 = 1 */ unsigned int...
BitField Variable Syntax
There are not equivalent: With: struct S1 { unsigned int a : 1; unsigned int b : 1; }; struct S2 { unsigned int a : 1, b : 1; }; struct S3 { unsigned int a; unsigned int b : 1; }; struct S4 { unsigned int a, b...
Signed bitfields require at least two bits
If you use the value as a flag, it's more logical to store it as unsigned since the normal expression would be 1 and 0, not -1 and 0. A logic expression in C also returns 1 if true, not -1 Another problem is that if you use signed bit...
operator[] overload in bit-field manipulation?
c++,operator-overloading,bit-fields
As has already been noted you can't bind a bit-field to a non-const reference. Since you're targeting the Arduino using std::bitset may not be a viable option depending on how much control you need over functionality or access to the data. There are a couple of things i want to...
Enforcing width of enum values within a struct in C99
Add a final tag to your enum definition: typedef enum { //... DUMMY_FORCE_WIDTH = 0xffffffffu, // INT_MAX, } color_t; That has the added benefit of forcing the compiler / ABI to give your enum enough space for growth everywhere. Of couse, that presupposes that your compiler allows enum's as bit-field...
Bit fields in C for signed integer-struct num { int a:3; int b:2; int c:1; }
Okay as you are a beginner, lets try to explain this.. The first one is int a : 3 which means that you are interested to store 3 bits, but in the main you are assigning the value 8.. Now the binary value of 8 is 1000 but as you...
Default values to bitfield elements
No, bit-fields do not allow an initializer as part of the member declaration. You can see this in the part of the grammar that describes class members (C++11 and later, [class.mem]): member-declarator: declarator virt-specifier-seqopt pure-specifieropt declarator brace-or-equal-initializeropt identifieropt attribute-specifier-seqopt : constant-expression The third form is the grammar for a bit-field...
How endianness effects on bitfields when a bitfield is greater than size of byte [duplicate]
c,struct,endianness,bit-fields
The compiler packs the bitfields as follows in the last two bytes: JJJJJJJJ00000KKKJ 00000010000000110 = 02 06 where the final J is the most significant bit of j. Note that almost everything about bitfields is implementation-defined or unspecified so you cannot rely on this. If you need total control of...
Reset all bits in a c bitfield
I would simply suggest: memset(&my_flags, 0, sizeof(myflags)); This way, you can still add fields to your structure, they will be reset thanks to sizeof....
Bit Fields in C
c,int,hex,bit-fields,negative-number
%x prints the hex representation of the value of the given argument. The two's complement representation of -1, in hex, gives you that ffffffff. FWIW: This outcome is not particularly related to use of bit-filed variable here, as printf() is a variadic function....
Size of a structure having unsigned short ints
Yes, this is bitfield, indeed. Well, i'm not very much sure about c++, but in c99 standard, as per chapter 6.7.2.1 (10): An implementation may allocate any addressable storage unit large enough to hold a bit-field. If enough space remains, a bit-field that immediately follows another bit-field in a structure...
Initializing bit-fields
c,struct,initialization,ansi,bit-fields
WRT "speaks about computation, not about initialization", the C89 standard explicitly applies the rules of assignment and conversion to initialization. It also says: A bit-field is interpreted as an integral type consisting of the specified number of bits. Given those, while a compiler warning would clearly be in order, it...
Storing 8 logical true/false values inside 1 byte?
All of your bitfield members are signed 1-bit integers. On a two's complement system, that means they can represent only either 0 or -1. Use uint8_t if you want 0 and 1: struct Bits { uint8_t b0:1, b1:1, b2:1, b3:1, b4:1, b5:1, b6:1, b7:1; }; ...
operator |= on std::vector
c++,bit-fields,boolean-operations
The main reason would be that std::vector<bool> is special, and its specification specifically permits an implementation to minimise memory usage. For vectors of anything other than bool, the reference type can actually be a true reference (i.e. std::vector<int>::reference can actually be an int &) - usually directly referencing an element...
the right way use bit field print number in binary
A bit-field shall have a type that is a qualified or unqualified version of _Bool, signed int, unsigned int, or some other implementation-defined type. Using unsigned char is allowable with some compilers as an "implementation-defined type". (p + length)->ch8 will go through the usual integer promotions being a parameters...
Memory location of bit-fields
c++,language-lawyer,bit-fields
No, they do not share any bit as they would in the union example. They just are considered one unit for the purposes of considering memory locations. Put another way, the following would be the bits in your example (potentially) AAAAAAAA BBBBBCCCCCCCCCCC DDDDDDDD EEEEEEEE (ee sharing e) The spaces are...
Issue with bit-fields
If you're working with bitfields, you should use unsigned int. signed int is a problem for bit-fields.
Translate from C to Delphi : struct fields align
that struct uses a C feature called bitfields where integers can have widths of fractional bytes. bitfields are not available in Delphi, see this answers to this question for details of how to do it using an object How to simulate bit-fields in Delphi records?...