I love C where types are basically a suggestion rather than a rule
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Exceptionally useful - you can do a cheap encryption by clever casting - or even more convenient, what might be considered an alias for casting: union And if one so chooses, passing ones data through a logical cuisinart is always appropriate. If you wish great power you must take great responsibility. As always.
"The difference between genius and stupidity is that genius has its limits." - Albert Einstein
"If you are searching for perfection in others, then you seek disappointment. If you seek perfection in yourself, then you will find failure." - Balboos HaGadol Mar 2010
I use unions sometimes, but i only needed the cast in two places in the code that inspired this post, and it was all it was ever going to need. :)
Real programmers use butterflies
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I had a legacy program that had void****** as part of a sort routine. It worked, i didn't now how. The guy that wrote it was long gone and i spent a afternoon trying to figure out how it worked. In the end i left it alone.
Member 14732673 wrote:
In the end i left it alone.
Really wise. Never touch a running system, unless you really know how to fix it :rolleyes: ;P :-D
M.D.V. ;) If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about? Help me to understand what I'm saying, and I'll explain it better to you Rating helpful answers is nice, but saying thanks can be even nicer.
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Such a right-thinking person. :thumbsup: Are you implying that there are languages that don't allow this, and force you to serialize using JSON or some other drool?! :-D
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The fox knows many things, but the hedgehog knows one big thing.something like that, yes. :-D
Real programmers use butterflies
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C# has been improving a lot in that area. You can take a `Span` of various types (some mostly-reasonable restrictions apply) and use `MemoryMarshal.AsBytes` on it to view it has a `Span`, then stash it in a file or whatever. It's nice. Actually paradoxically it's nicer than in C, because in C# you can actually control the layout of fields to whatever degree you need, so you can use this for file headers that have "unaligned" fields. C# is a better low level language than C.
Does it mandate the endianism and take the hit on non-compliant platforms, or is it still a problem for intersystem messages?
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The fox knows many things, but the hedgehog knows one big thing. -
[Program: Shoot in foot](http://www.personal.psu.edu/sxt104/program1.html)
Freedom is the freedom to say that two plus two make four. If that is granted, all else follows. -- 6079 Smith W.
Quote:
Assembler: You try to shoot yourself in the foot, only to discover you must first invent the gun, the bullet, the trigger, and your foot. Modula2: After realizing that you can't actually accomplish anything in this language, you shoot yourself in the head.
:laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :thumbsup::thumbsup::thumbsup::thumbsup:
M.D.V. ;) If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about? Help me to understand what I'm saying, and I'll explain it better to you Rating helpful answers is nice, but saying thanks can be even nicer.
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The cast operator is why I can cast my struct directly to an "array" of bytes and stash it in a file. It makes me happy. It's so elegant. So concise. And so dangerous.
Real programmers use butterflies
Yes to all of that. Elegant and concise. C++ is much more type safe, and yet it became heavy: hard to read and often very hard to write, a bit constrictive. C is absolute freedom, total power... and requires total responsibility.
GCS d--(d+) s-/++ a C++++ U+++ P- L+@ E-- W++ N+ o+ K- w+++ O? M-- V? PS+ PE- Y+ PGP t+ 5? X R+++ tv-- b+(+++) DI+++ D++ G e++ h--- r+++ y+++* Weapons extension: ma- k++ F+2 X
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The cast operator is why I can cast my struct directly to an "array" of bytes and stash it in a file. It makes me happy. It's so elegant. So concise. And so dangerous.
Real programmers use butterflies
Then there are unions. Essentially a compiler-driven cast with no type conversions what so ever. It's in-memory aliasing. It takes casting to an entirely new level. I have found many good uses for unions. So has Microsoft - see the LARGE_INTEGER for an example.
"They have a consciousness, they have a life, they have a soul! Damn you! Let the rabbits wear glasses! Save our brothers! Can I get an amen?"
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Does it mandate the endianism and take the hit on non-compliant platforms, or is it still a problem for intersystem messages?
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The fox knows many things, but the hedgehog knows one big thing. -
The cast operator is why I can cast my struct directly to an "array" of bytes and stash it in a file. It makes me happy. It's so elegant. So concise. And so dangerous.
Real programmers use butterflies
yeah, that'll work so long as you don't stash your structs pointers this way. :)
#SupportHeForShe Government can give you nothing but what it takes from somebody else. A government big enough to give you everything you want is big enough to take everything you've got, including your freedom.-Ezra Taft Benson You must accept 1 of 2 basic premises: Either we are alone in the universe or we are not alone. Either way, the implications are staggering!-Wernher von Braun
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Unfortunately it's always in the native endianness, with no way to control it. An attribute for that is on my wishlist.
The proprietary language in which I worked for many years standardized its endianism and took the hit, so intersystem messaging was easy. It was designed when memory was precious--unlike today :)--so it was easy to control packing. For example, a
boolwas a single bit, and anenumcould be packed into the fewest bits needed for its enumerators (negative values not allowed). We would only pad a field when performance was critical.Robust Services Core | Software Techniques for Lemmings | Articles
The fox knows many things, but the hedgehog knows one big thing. -
Member 14732673 wrote:
In the end i left it alone.
Really wise. Never touch a running system, unless you really know how to fix it :rolleyes: ;P :-D
M.D.V. ;) If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about? Help me to understand what I'm saying, and I'll explain it better to you Rating helpful answers is nice, but saying thanks can be even nicer.
That's the fun! Make a change and watch it break and fix the break is the only way to understand ancient code.
#SupportHeForShe Government can give you nothing but what it takes from somebody else. A government big enough to give you everything you want is big enough to take everything you've got, including your freedom.-Ezra Taft Benson You must accept 1 of 2 basic premises: Either we are alone in the universe or we are not alone. Either way, the implications are staggering!-Wernher von Braun
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Then there are unions. Essentially a compiler-driven cast with no type conversions what so ever. It's in-memory aliasing. It takes casting to an entirely new level. I have found many good uses for unions. So has Microsoft - see the LARGE_INTEGER for an example.
"They have a consciousness, they have a life, they have a soul! Damn you! Let the rabbits wear glasses! Save our brothers! Can I get an amen?"
Yeah, I'm aware - I even adapted the approach for C# using StructLayout.Explicit. It's just that declaring a union type isn't always called for. If you're doing the cast once or twice it doesn't make a lot of sense, so i do it when it's called for.
Real programmers use butterflies
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yeah, that'll work so long as you don't stash your structs pointers this way. :)
#SupportHeForShe Government can give you nothing but what it takes from somebody else. A government big enough to give you everything you want is big enough to take everything you've got, including your freedom.-Ezra Taft Benson You must accept 1 of 2 basic premises: Either we are alone in the universe or we are not alone. Either way, the implications are staggering!-Wernher von Braun
Yeah I try not to point into the stack for longer than the context of the containing function. :laugh:
Real programmers use butterflies
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Yes to all of that. Elegant and concise. C++ is much more type safe, and yet it became heavy: hard to read and often very hard to write, a bit constrictive. C is absolute freedom, total power... and requires total responsibility.
GCS d--(d+) s-/++ a C++++ U+++ P- L+@ E-- W++ N+ o+ K- w+++ O? M-- V? PS+ PE- Y+ PGP t+ 5? X R+++ tv-- b+(+++) DI+++ D++ G e++ h--- r+++ y+++* Weapons extension: ma- k++ F+2 X
den2k88 wrote:
C++ is ... hard to read and often very hard to write
Am I using it wrong, because I've never had these problems?
“If we get $100,000, we will go to Potato blockchain.” Enable the dream!
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den2k88 wrote:
C++ is ... hard to read and often very hard to write
Am I using it wrong, because I've never had these problems?
“If we get $100,000, we will go to Potato blockchain.” Enable the dream!
Funny, I was thinking the same things. But then again, I've encountered code like the OP described. Usually written by electrical engineers.
#SupportHeForShe Government can give you nothing but what it takes from somebody else. A government big enough to give you everything you want is big enough to take everything you've got, including your freedom.-Ezra Taft Benson You must accept 1 of 2 basic premises: Either we are alone in the universe or we are not alone. Either way, the implications are staggering!-Wernher von Braun
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Funny, I was thinking the same things. But then again, I've encountered code like the OP described. Usually written by electrical engineers.
#SupportHeForShe Government can give you nothing but what it takes from somebody else. A government big enough to give you everything you want is big enough to take everything you've got, including your freedom.-Ezra Taft Benson You must accept 1 of 2 basic premises: Either we are alone in the universe or we are not alone. Either way, the implications are staggering!-Wernher von Braun
:laugh: You mean C++ that is no more than C or, even worse, FORTRAN?
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The fox knows many things, but the hedgehog knows one big thing. -
den2k88 wrote:
C++ is ... hard to read and often very hard to write
Am I using it wrong, because I've never had these problems?
“If we get $100,000, we will go to Potato blockchain.” Enable the dream!
Well, some of the template stuff out there... :wtf:
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The fox knows many things, but the hedgehog knows one big thing. -
yeah, that'll work so long as you don't stash your structs pointers this way. :)
#SupportHeForShe Government can give you nothing but what it takes from somebody else. A government big enough to give you everything you want is big enough to take everything you've got, including your freedom.-Ezra Taft Benson You must accept 1 of 2 basic premises: Either we are alone in the universe or we are not alone. Either way, the implications are staggering!-Wernher von Braun
No problem. Placement
newto the rescue! Sorry, wrong language. :laugh:Robust Services Core | Software Techniques for Lemmings | Articles
The fox knows many things, but the hedgehog knows one big thing. -
The cast operator is why I can cast my struct directly to an "array" of bytes and stash it in a file. It makes me happy. It's so elegant. So concise. And so dangerous.
Real programmers use butterflies
the file is also not compatible between architecture to the next! :( i.e. endianess for sure.. but probably computer struct paddings too! :/ though haven't used C in decades, so I am not so sure about that one...
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the file is also not compatible between architecture to the next! :( i.e. endianess for sure.. but probably computer struct paddings too! :/ though haven't used C in decades, so I am not so sure about that one...
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Sometimes that doesn't matter. Sometimes you're writing software dedicated to a particular microcontroller and it expects the thing to be wired a certain way in order to run anyway.
Real programmers use butterflies
