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No, C is not the same as it is less expressive. C++ templates allow for declarative nested inlining into a single compilation unit that is extremely difficult

No, C is not the same as it is less expressive. C++ templates allow for declarative nested inlining into a single compilation unit that is extremely difficult to achieve with C macros. See elsewhere in this thread for discussion of boost, it's not applicable.

stefan_ 3y ago
In this thread: all the people that have never looked at C++ disassembly. Maybe the C++ "language server" of your choice should have a mode where it prints all the constructors destructors copy constructors and what not on top of your code? "Zero cost abstraction" is a big fantasy. C++ is the king of hidden control flow and the costs are everywhere.
- CoolGuySteve 3y ago
  Thanks for the shitty attitude but it sounds more like you're looking at the disassembly of debug builds or don't understand how constexpr/consteval work.
- RcouF1uZ4gsC 3y ago
  > In this thread: all the people that have never looked at C++ disassembly. Maybe the C++ "language server" of your choice should have a mode where it prints all the constructors destructors copy constructors and what not on top of your code? That tool is called Godbolt at gcc.godbolt.org. This is common enough that Godbolt is a verb with a lot of C++ programmers.
- IAmLiterallyAB 3y ago
  As someone who reads C++ disassembly/decompilation for a living... Yeah kinda. It depends. If the target code is full of virtual function calls, yeah it gets gross. But if you need dynamic dispatch, C isn't going to be any better, you'll just be reinventing vtables by hand. Similarly, resource acquisition and release happens in C too, you just have to do it by hand instead of letting the destructor do it for you. One ultra gross thing I see all the time in C++ disassembly though: constantly creating copies of a std::string, using them once for a comparison or something trivial, and then throwing them away. Multiple times in the same function. Its the developers fault, they shouldn't be creating new objects, they should be passing a pointer or a string_view or something. Unfortunately, C++ is copy rather than move by default, so its too easy to do this by accident. Another gross thing? (Not C++ specific) 20 functions in a row that are just a single return instruction. Since functions have to have distinct addresses (that's my understanding at least) the compiler/linker can't easily fold identical functions together. Implementations can optimize as long as everything still works (the "as-if" rule). And I know some compilers do. But in practice, it seems they suck at it. So I get to look at 20 lines of assembly in a row that are just `bl`.
- rewmie 3y ago
  [dead]
rightbyte 3y ago
In practice the Sufficiently Smart Compiler will have a hard time optimizing all these layers. C macros are way simpler as they are only text. I still use them alot in C++.

stefan_ 3y ago

In this thread: all the people that have never looked at C++ disassembly. Maybe the C++ "language server" of your choice should have a mode where it prints all the constructors destructors copy constructors and what not on top of your code? "Zero cost abstraction" is a big fantasy. C++ is the king of hidden control flow and the costs are everywhere.

CoolGuySteve 3y ago
Thanks for the shitty attitude but it sounds more like you're looking at the disassembly of debug builds or don't understand how constexpr/consteval work.
RcouF1uZ4gsC 3y ago
> In this thread: all the people that have never looked at C++ disassembly. Maybe the C++ "language server" of your choice should have a mode where it prints all the constructors destructors copy constructors and what not on top of your code? That tool is called Godbolt at gcc.godbolt.org. This is common enough that Godbolt is a verb with a lot of C++ programmers.
IAmLiterallyAB 3y ago
As someone who reads C++ disassembly/decompilation for a living... Yeah kinda. It depends. If the target code is full of virtual function calls, yeah it gets gross. But if you need dynamic dispatch, C isn't going to be any better, you'll just be reinventing vtables by hand. Similarly, resource acquisition and release happens in C too, you just have to do it by hand instead of letting the destructor do it for you. One ultra gross thing I see all the time in C++ disassembly though: constantly creating copies of a std::string, using them once for a comparison or something trivial, and then throwing them away. Multiple times in the same function. Its the developers fault, they shouldn't be creating new objects, they should be passing a pointer or a string_view or something. Unfortunately, C++ is copy rather than move by default, so its too easy to do this by accident. Another gross thing? (Not C++ specific) 20 functions in a row that are just a single return instruction. Since functions have to have distinct addresses (that's my understanding at least) the compiler/linker can't easily fold identical functions together. Implementations can optimize as long as everything still works (the "as-if" rule). And I know some compilers do. But in practice, it seems they suck at it. So I get to look at 20 lines of assembly in a row that are just `bl`.
rewmie 3y ago
[dead]

rightbyte 3y ago

In practice the Sufficiently Smart Compiler will have a hard time optimizing all these layers. C macros are way simpler as they are only text. I still use them alot in C++.