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For those who wants to know c++17 features http://stackoverflow.com/questions/38060436/what-are-the-new-features-in-c17 http://stackoverflow.com/questions/3806

For those who wants to know c++17 features http://stackoverflow.com/questions/38060436/what-are-the-new-features-in-c17 http://stackoverflow.com/questions/38060436/what-are-the-new... std::optional and std::any are one of the good things. std::apply and std::invoke can help you write better functional c++17 code. Anyway thanks for C++17. For sometime, I thought I will learn Rust.

stinos 10y ago
That SO question has barely any code examples but mostly links to sometimes quite technical documents. I'd really love to see a comprehensive list of all features (if possible c++11, 14 and 17) together with small explanation + code samples: even though I am already using a lot of the new features I still feel like I'm missing out on certain things just because I don't know they exist and because the information is shattered. (e.g. I'm fairly sure SO has Q&A on like every new feature, but it would take an insane amount of time to go through every question tagged [c++17]).
- asitdhal 10y ago
  I don't know if similar things existed for C++11/14. But, it doesn't exist for C++17. I faced the similar problem. I invested some money in Effective Modern C++(Scott Mayer). It covers the language part. I borrowed a book for C++11 concurrency. But, modern C++ lacks high-quality material at one place like Golang/Rust(the language guys have very good documentation, not boring and good enough to learn quickly). There are tons of scattered example.
- surye 10y ago
  https://github.com/tvaneerd/cpp17_in_TTs/blob/master/ALL_IN_ONE.md https://github.com/tvaneerd/cpp17_in_TTs/blob/master/ALL_IN_... This comes pretty close to what you're asking for I believe.
  - stinos 10y ago
    Yes, thanks, that's bascially the sort of thing I was looking for!
- brcha 10y ago
  cppreference.com usually has [c++XYZ] marks on features introduced by a specific version of C++ and it is usually current with updates while having some basic examples for most things. The site doesn't have a comprehensive list of all the features introduced in the specific version of C++, but which ever feature is interesting to you should be easy to find there.
tmyklebu 10y ago
In modern gcc, std::variant doesn't look like a competent replacement for old-fashioned tagged unions. On x86_64 Linux, it looks like a function with signature `void f(std::variant<int, char>)` expects its (8-byte) argument to be passed by reference, whereas `void f2(tagged_union_of_int_and_char)` passes its argument in rdi. gcc (-O3) also generates miserable code for calling f(42): 4004f0: 48 83 ec 18 sub $0x18,%rsp 4004f4: 48 89 e7 mov %rsp,%rdi 4004f7: c7 04 24 2a 00 00 00 movl $0x2a,(%rsp) 4004fe: c6 44 24 04 00 movb $0x0,0x4(%rsp) 400503: e8 c8 ff ff ff callq 4004d0 <f> 400508: 48 83 c4 18 add $0x18,%rsp 40050c: c3 retq as compared with calling f2(42): 400510: 48 bf 00 00 00 00 2a movabs $0x2a00000000,%rdi 400517: 00 00 00 40051a: eb c4 jmp 4004e0 <f2> std::optional seems to have the same disease; the ABI is different from a plain struct containing a bool and the value and you get worse initialisation code. There's also a build time penalty to using std::optional; on my machine, including the code that uses optionals makes my trivial test program take 320ms to compile and link rather than 50ms. These look like yet more new C++ features that are worse than what they're trying to replace.
- Sharlin 10y ago
  Eh, I get that one of the points of C++ is to minimize abstraction penalty even when you do use abstractions, but these things are compromises. In almost all real-world software development the advantages of abstraction far outweigh micro-optimizations that shave off individual cycles...
  - tmyklebu 10y ago
    Writing ad-hoc tagged unions and two-element 'optional' structs is a completely straightforward mechanical task---exactly the sort of thing that a programming language ought to automate. Why does there need to be a "compromise" between boilerplate and performance here? Why should I have to pay performance to use standard tagged unions and optionals, or conversely, pay by writing boilerplate in order to get performance?
  - wolf550e 10y ago
poland2 10y ago
I hope c++20 will be c++18 ：）
- adrift 10y ago
  Don't worry, it won't be.
deleted 10y ago
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deleted 10y ago
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YZF 10y ago
This has been in Boost for a while now so doesn't really change much.

stinos 10y ago

That SO question has barely any code examples but mostly links to sometimes quite technical documents. I'd really love to see a comprehensive list of all features (if possible c++11, 14 and 17) together with small explanation + code samples: even though I am already using a lot of the new features I still feel like I'm missing out on certain things just because I don't know they exist and because the information is shattered. (e.g. I'm fairly sure SO has Q&A on like every new feature, but it would take an insane amount of time to go through every question tagged [c++17]).

asitdhal 10y ago
I don't know if similar things existed for C++11/14. But, it doesn't exist for C++17. I faced the similar problem. I invested some money in Effective Modern C++(Scott Mayer). It covers the language part. I borrowed a book for C++11 concurrency. But, modern C++ lacks high-quality material at one place like Golang/Rust(the language guys have very good documentation, not boring and good enough to learn quickly). There are tons of scattered example.
surye 10y ago
https://github.com/tvaneerd/cpp17_in_TTs/blob/master/ALL_IN_ONE.md https://github.com/tvaneerd/cpp17_in_TTs/blob/master/ALL_IN_... This comes pretty close to what you're asking for I believe.
- stinos 10y ago
  Yes, thanks, that's bascially the sort of thing I was looking for!
brcha 10y ago
cppreference.com usually has [c++XYZ] marks on features introduced by a specific version of C++ and it is usually current with updates while having some basic examples for most things. The site doesn't have a comprehensive list of all the features introduced in the specific version of C++, but which ever feature is interesting to you should be easy to find there.

tmyklebu 10y ago

In modern gcc, std::variant doesn't look like a competent replacement for old-fashioned tagged unions. On x86_64 Linux, it looks like a function with signature `void f(std::variant<int, char>)` expects its (8-byte) argument to be passed by reference, whereas `void f2(tagged_union_of_int_and_char)` passes its argument in rdi. gcc (-O3) also generates miserable code for calling f(42): 4004f0: 48 83 ec 18 sub $0x18,%rsp 4004f4: 48 89 e7 mov %rsp,%rdi 4004f7: c7 04 24 2a 00 00 00 movl $0x2a,(%rsp) 4004fe: c6 44 24 04 00 movb $0x0,0x4(%rsp) 400503: e8 c8 ff ff ff callq 4004d0 <f> 400508: 48 83 c4 18 add $0x18,%rsp 40050c: c3 retq as compared with calling f2(42): 400510: 48 bf 00 00 00 00 2a movabs $0x2a00000000,%rdi 400517: 00 00 00 40051a: eb c4 jmp 4004e0 <f2> std::optional seems to have the same disease; the ABI is different from a plain struct containing a bool and the value and you get worse initialisation code. There's also a build time penalty to using std::optional; on my machine, including the code that uses optionals makes my trivial test program take 320ms to compile and link rather than 50ms. These look like yet more new C++ features that are worse than what they're trying to replace.

Sharlin 10y ago
Eh, I get that one of the points of C++ is to minimize abstraction penalty even when you do use abstractions, but these things are compromises. In almost all real-world software development the advantages of abstraction far outweigh micro-optimizations that shave off individual cycles...
- tmyklebu 10y ago
  Writing ad-hoc tagged unions and two-element 'optional' structs is a completely straightforward mechanical task---exactly the sort of thing that a programming language ought to automate. Why does there need to be a "compromise" between boilerplate and performance here? Why should I have to pay performance to use standard tagged unions and optionals, or conversely, pay by writing boilerplate in order to get performance?
- wolf550e 10y ago

poland2 10y ago

I hope c++20 will be c++18 ：）

adrift 10y ago
Don't worry, it won't be.

deleted 10y ago

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deleted 10y ago

[deleted]

YZF 10y ago

This has been in Boost for a while now so doesn't really change much.