I don’t like that “C++ isn’t memory safe”. It is. Users of that language are usually just not experienced or educated enough and therefore more mistakes happen.
I agree though, that other languages like Rust or Java can make it easier to prevent such mistakes.
In my experience, using smart pointers alone already solves 90% of memory issues I have to deal with. C++ improved a lot in that regard over the decades.
I’m very experienced with C++and I still feel like I’m juggling chainsaws every time I use it. And I’ve personally run into into things like use after free errors while working in Chromium. It’s a massive codebase full of multithreading, callbacks, and nonlocal effects. Managing memory may be easy in a simple codebase but it’s a nightmare in Chromium. Tools like AddressSanitizer are a routine part of Chrome development for exactly that reason. And people who think memory management is easy in C++ are precisely the people I expect to introduce a lot of bugs.
I’ve a very long track record using C++ as well and I can’t share the feeling. I don’t say it’s alyways easy. I’m just saying that it’s doable and therefore whether the software is memory safe depends on the expertise of the devs.
Modern C++ practises, programming patterns and as well tools from the STL (or even your own implementation) make life a lot easier. If you don’t use them, that’s not the languages fault. In the end, how you use the language still matters a lot.
If you’d like to think less about memory management, go on and use Rust or C# or Java or even Python if performance doesn’t matter. That’s perfectly fine. This can come with other issues, like more boilerplate in the case of Rust for example, but in the end those languages are tools. Choose the tool which gets your job done.
I don’t think this solely depends on the level of experience. People make mistakes, and these kinds of mistakes are very hard to find. And don’t tell me you are the perfect coder that makes no mistakes, introduces no bugs.
whether the software is memory safe depends on the expertise of the devs
No. Just stop. If a language depends on the expertise of the developer to be free of memory bugs, then by definition, it is not memory safe because memory safety means such bugs are impossible by design. Quit trying to redefine what memory safety means. A program being free of memory bugs does not in any way imply memory safety.
I agree that experienced users can write code that leaks less than in C, leaving aside the bottomless pit of despair that is undefined behaviour. But the the language isn’t memory safe, it doesn’t even prevent you from returning a reference to a local or helpnwitg iterator invalidation. you don’t have to jump through any hoops to enable making that mistake.
If a language prevents you from doing stuff like that, this always comes at a cost, since it has to do the work for you, almost always. This is additional overhead you can get rid of in C++ and therefore gain a lot of performance. But that again comes with more responsibility on the developer’s side and you might need to implement appropriate checks yourself where needed.
Rust prevents the things mentioned above in the compiler; there is no runtime cost for most of Rust’s safety measures. There is definitely a build time cost though.
You can unsafe your way around anything, but that’s on the dev.
I’m not just talking about performance costs.
For example, compared to C++, Rust comes with reduced flexibility and increased complexity in certain cases.
The borrow checker, for example, imposes strict ownership and lifetime rules, which can be difficult to work with, especially in complex data structures or when interfacing with existing systems. Sometimes, you have to significantly refactor your code just to satisfy these constraints, even when you know the code would be safe in practice. This can slow down development, require more boilerplate, and make certain patterns harder to express.
C++ gives developers more freedom but expects them to take responsibility. That tradeoff isn’t just about raw performance; it’s also about how much control and convenience the developer has.
You said performance, so I responded to that. You can dislike Rust, that’s fine, but a lot of the things you’re saying aren’t correct. C++ isn’t memory safe, the person responding before showed that pretty easily. Rust doesn’t perform slower than C++, I responded to that claim. Rust provides tools to be memory safe, but the existence of unsafe I’d argue makes it also not memory safe, but at least better than C/C++. It also has tons of undefined behavior, just like those two.
As for the personal opinion; you don’t have to like Rust. I actually have a very different view of the borrow checker and I don’t think I’ve ever “fought” it in a time when I was also doing something inherently safe. Every time I’ve had an issue with satisfying the borrow checker, which is rare, it’s been because I was doing something unsafe or interacting with C code, which Rust would argue is also unsafe. In my experience, it really eases the burden of programming actually and it makes debugging easier. It also makes design easier. As an example, I’ve been working on a very large C project recently and I ran into a bug where I was getting the wrong data printed out when I checked a value. After looking into it for like 15 minutes, I finally figured out that I had accidentally passed a stack pointer to a function that I wrote expecting a heap pointer. When the function went out of scope the data was garbage, but there was no crash and no compiler error. The borrow checker would have helpfully stopped me in my tracks there and saved that 15 minutes of debugging. The fact that it’s hard to implement your own efficient linked list or vector type has never been a problem for me really, especially not in comparison to the gains of not always having to keep ownership and lifetimes of pointers in my own head or in documentation that may go stale. I can’t express enough how helpful that is to my programming experience. C puts the burden of pointer lifetimes and ownership entirely on the developer. C++ makes that a bit better with the smart pointers at least, but those have some rules that aren’t enforced by the compiler but instead by convention.
Basically I find the phrase “fighting the borrow checker” to be shorthand for “I can’t write C or C++ in Rust and I want to”. They’re not the same language and the constructs are different
That was not the only aspect, but yes, I mentioned that.
I don’t dislike Rust. I find it pretty cool. However, I disagree with the blanket statement “C++ isn’t memory safe”. C++ provides the tools for writing memory-safe code, but it does not enforce it by default. That’s a design choice: favoring flexibility over strict enforcement.
Yes, you can make mistakes that lead to memory issues. But that’s not a problem with the language itself; it with how it’s used. Stupid example: if you write code, which divides by zero at some point and you don’t make sure to check that, this is not the language’s fault, but your own.
Of course a language can accomodate for stuff like that and lift some of that burden from the user. Surely there are plenty of use cases and user groups for that. And that’s totally okay. Rust was designed with memory safety in mind to prevent common errors that occur to a lot of devs during the usage of C++, which is fair. But that doesn’t make C++ less memory safe. It is intentionally open and flexible on purpose. There are various programming patterns and even functionality within the STL that help to prevent memory issues.
So in other words: C++ is a tool, just like Rust. If you don’t know how to use the tool, that’s not the tool’s fault.
C++ makes that a bit better with the smart pointers at least, but those have some rules that aren’t enforced by the compiler but instead by convention.
You can always implement your own smart pointers. Besides that: which conventions do you mean?
Basically I find the phrase “fighting the borrow checker” to be shorthand for “I can’t write C or C++ in Rust and I want to”.
Nah, although it has its persk, I just think that it also imposes a rigid framework that sometimes forces you into cumbersome workarounds. With C++, you retain full control over memory management and can choose the best tool for the job. You’re not boxed into a strict ownership model that may force refactoring or add extra layers of abstraction. Instead, you have a mature ecosystem with decades of evolution that lets you balance safety and control based on context. Sure, mistakes can happen, but with proper practices and modern C++ features you can achieve a level of safety that meets most needs without sacrificing the expressiveness and efficiency you might require in complex systems.
I disagree with the blanket statement “C++ isn’t memory safe”. C++ provides the tools for writing memory-safe code, but it does not enforce it by default.
This is such a weird take. C++ isn’t memory safe. The blanket statement is… true. You say as much in the second sentence.
With C++, you retain full control over memory management and can choose the best tool for the job. You’re not boxed into a strict ownership model that may force refactoring or add extra layers of abstraction.
You have full control in Rust too, at least to the same extent as C++. Rust isn’t memory safe either. Rust is just the opposite of C++ in the approach to safety: you opt in to being unsafe with the unsafe construct instead of being unsafe by default. They’re just different paradigms. I’d actually argue that you don’t have full control in either language unless you opt in to it, modern C++ tries very hard to abstract away memory management. You can write an entire program without a single new or malloc, which is pretty great.
Sure, mistakes can happen, but with proper practices and modern C++ features you can achieve a level of safety that meets most needs without sacrificing the expressiveness and efficiency you might require in complex systems.
This is just simply not true and is consistently proven incorrect every time an aspect of C++'s memory unsafety is exploited. I work in security and I still, in 2025, exploit memory corruption. The best developers money can buy still make mistakes with C and C++.
Besides that: which conventions do you mean?
The way you have to interact with smart pointers for example:
Double free, but compiles without warning. It’s convention to not use unique_pointer’s constructor, not enforced.
#include<iostream>#include<string>intmain(int argc, char** argv){
constchar* c;
{
std::string a("HelloThisIsAHeapString");
c = a.c_str();
}
std::cout << c << std::endl;
}
Use after free. No compiler error or warning, it’s convention to not maintain references to C++ string data, not enforced.
That’s all fine, whatever, but these are conventions. We’ve shot ourselves in the foot a million times and come up with our own guard rails, but the developer needs to know all of them to not make the mistake.
This is such a weird take. C++ isn’t memory safe. The blanket statement is… true. You say as much in the second sentence.
I suppose we need to make definitions clearer. C++ is memory safe in the sense that you can write memory safe code. It doesn’t enforce memory safety though. But not doing that is not the language’s fault. If someone jumps with a bike from a flying airplane, it’s not the bike’s fault that they will not land safely. It’s the misuse of the bike.
The best developers money can buy still make mistakes with C and C++.
I’d argue those weren’t the best developers then. However, I don’t want to get ridiculous. I see that there are problems in the common use of C++. Although I can’t share that from my experience due to usually proper usage, thorough testing use of additional tools, there is surely a need for aiding C++ devs with writing safe code. I know of the corresponding security concerns as well as probably everyone else in the C++ community.
There are proposals to improve on that. Some of those might already come with C++26. Stroustrup’s favourite are Profiles to provide and enforce further guarantees, while others propsed an extension like Safe C++. Whereever the future will take us with C++, I’m confident that this issue will be sufficiently solved one day.
There was a time when C++ wasn’t even designed for multi-processor systems, lol. That was redesigned pretty late. Much has changed and it will continue to improve as C++ continues to mature.
Edit:
Just saw your convention examples after I’ve sent my reply. Idk why it wasn’t displayed before.
Regarding the double free:
It’s clear from the documentation that this returns a raw pointer.
Regarding the use after free:
I really don’t want to sound arrogant as this is a simple example of course, but that is such an obvious mistake and looks like a topic which is covered in C++ beginner classes. To me, this is almost on the same level as dividing by zero and wondering about resulting bugs.
but the developer needs to know all of them to not make the mistake
Yes. Not every language is as user-friendly as python. With more flexibility come more risks but also more rewards if you’ve mastered it. It depends on what you want to do and how much you’re willing to invest.
I would at least expect a professional dev to rtfm. Which itself is apparently already a problem. But, in the end of the day we want to use tools, which are effective and easy to use. So sure, point taken. I refer to the section before my edit regarding developments upon improving such aspects in C++.
sure, maybe, but performance doesn’t matter for deciding if a language is memory-safe or not. And C++ isn’t memory-safe by any commonly used interpretation of that word.
You may of course decide that the downsides of memory-safety aren’t worth it for your use-case, that is a separate issue
I think it boils down, how we define “memory safe”. C++ is perfectly memory safe, if you know what you’re doing. A lot of people don’t. Which is why Rust was born. that doesn’t make C++ a memory-unsafe language. It just demands more responsibility from the user. A design philosophy that comes with a lot more flexibility than Rust can offer.
Which is fine. Both languages have their perks. But saying C++ isn’t memory safe, while Rust is, is in my opinion just plainly wrong. Besides, with “unsafe” Rust inherently already the door for memory issues.
Modern C++ practises and dev patterns can handle most memory issues in C++ pretty easily. Consider smart pointers for example, or RAII.
It’s not the language’s fault if it is used wrong.
Which language would you say is not memory safe then? Is there any serious language out there where you should expect memory issues if you don’t make any mistakes?
If the standard is “you know what you’re doing and never make mistakes”, then all languages are memory safe. All you’re doing is arguing against memory safety as a concept by redefining the term in such a way that it becomes meaningless.
I don’t like that “C++ isn’t memory safe”. It is. Users of that language are usually just not experienced or educated enough and therefore more mistakes happen.
I agree though, that other languages like Rust or Java can make it easier to prevent such mistakes.
In my experience, using smart pointers alone already solves 90% of memory issues I have to deal with. C++ improved a lot in that regard over the decades.
I’m very experienced with C++and I still feel like I’m juggling chainsaws every time I use it. And I’ve personally run into into things like use after free errors while working in Chromium. It’s a massive codebase full of multithreading, callbacks, and nonlocal effects. Managing memory may be easy in a simple codebase but it’s a nightmare in Chromium. Tools like AddressSanitizer are a routine part of Chrome development for exactly that reason. And people who think memory management is easy in C++ are precisely the people I expect to introduce a lot of bugs.
I’ve a very long track record using C++ as well and I can’t share the feeling. I don’t say it’s alyways easy. I’m just saying that it’s doable and therefore whether the software is memory safe depends on the expertise of the devs. Modern C++ practises, programming patterns and as well tools from the STL (or even your own implementation) make life a lot easier. If you don’t use them, that’s not the languages fault. In the end, how you use the language still matters a lot. If you’d like to think less about memory management, go on and use Rust or C# or Java or even Python if performance doesn’t matter. That’s perfectly fine. This can come with other issues, like more boilerplate in the case of Rust for example, but in the end those languages are tools. Choose the tool which gets your job done.
I don’t think this solely depends on the level of experience. People make mistakes, and these kinds of mistakes are very hard to find. And don’t tell me you are the perfect coder that makes no mistakes, introduces no bugs.
No. Just stop. If a language depends on the expertise of the developer to be free of memory bugs, then by definition, it is not memory safe because memory safety means such bugs are impossible by design. Quit trying to redefine what memory safety means. A program being free of memory bugs does not in any way imply memory safety.
I agree that experienced users can write code that leaks less than in C, leaving aside the bottomless pit of despair that is undefined behaviour. But the the language isn’t memory safe, it doesn’t even prevent you from returning a reference to a local or helpnwitg iterator invalidation. you don’t have to jump through any hoops to enable making that mistake.
If a language prevents you from doing stuff like that, this always comes at a cost, since it has to do the work for you, almost always. This is additional overhead you can get rid of in C++ and therefore gain a lot of performance. But that again comes with more responsibility on the developer’s side and you might need to implement appropriate checks yourself where needed.
Rust prevents the things mentioned above in the compiler; there is no runtime cost for most of Rust’s safety measures. There is definitely a build time cost though.
You can unsafe your way around anything, but that’s on the dev.
I’m not just talking about performance costs. For example, compared to C++, Rust comes with reduced flexibility and increased complexity in certain cases.
The borrow checker, for example, imposes strict ownership and lifetime rules, which can be difficult to work with, especially in complex data structures or when interfacing with existing systems. Sometimes, you have to significantly refactor your code just to satisfy these constraints, even when you know the code would be safe in practice. This can slow down development, require more boilerplate, and make certain patterns harder to express.
C++ gives developers more freedom but expects them to take responsibility. That tradeoff isn’t just about raw performance; it’s also about how much control and convenience the developer has.
You said performance, so I responded to that. You can dislike Rust, that’s fine, but a lot of the things you’re saying aren’t correct. C++ isn’t memory safe, the person responding before showed that pretty easily. Rust doesn’t perform slower than C++, I responded to that claim. Rust provides tools to be memory safe, but the existence of
unsafeI’d argue makes it also not memory safe, but at least better than C/C++. It also has tons of undefined behavior, just like those two.As for the personal opinion; you don’t have to like Rust. I actually have a very different view of the borrow checker and I don’t think I’ve ever “fought” it in a time when I was also doing something inherently safe. Every time I’ve had an issue with satisfying the borrow checker, which is rare, it’s been because I was doing something unsafe or interacting with C code, which Rust would argue is also unsafe. In my experience, it really eases the burden of programming actually and it makes debugging easier. It also makes design easier. As an example, I’ve been working on a very large C project recently and I ran into a bug where I was getting the wrong data printed out when I checked a value. After looking into it for like 15 minutes, I finally figured out that I had accidentally passed a stack pointer to a function that I wrote expecting a heap pointer. When the function went out of scope the data was garbage, but there was no crash and no compiler error. The borrow checker would have helpfully stopped me in my tracks there and saved that 15 minutes of debugging. The fact that it’s hard to implement your own efficient linked list or vector type has never been a problem for me really, especially not in comparison to the gains of not always having to keep ownership and lifetimes of pointers in my own head or in documentation that may go stale. I can’t express enough how helpful that is to my programming experience. C puts the burden of pointer lifetimes and ownership entirely on the developer. C++ makes that a bit better with the smart pointers at least, but those have some rules that aren’t enforced by the compiler but instead by convention.
Basically I find the phrase “fighting the borrow checker” to be shorthand for “I can’t write C or C++ in Rust and I want to”. They’re not the same language and the constructs are different
That was not the only aspect, but yes, I mentioned that.
I don’t dislike Rust. I find it pretty cool. However, I disagree with the blanket statement “C++ isn’t memory safe”. C++ provides the tools for writing memory-safe code, but it does not enforce it by default. That’s a design choice: favoring flexibility over strict enforcement.
Yes, you can make mistakes that lead to memory issues. But that’s not a problem with the language itself; it with how it’s used. Stupid example: if you write code, which divides by zero at some point and you don’t make sure to check that, this is not the language’s fault, but your own.
Of course a language can accomodate for stuff like that and lift some of that burden from the user. Surely there are plenty of use cases and user groups for that. And that’s totally okay. Rust was designed with memory safety in mind to prevent common errors that occur to a lot of devs during the usage of C++, which is fair. But that doesn’t make C++ less memory safe. It is intentionally open and flexible on purpose. There are various programming patterns and even functionality within the STL that help to prevent memory issues.
So in other words: C++ is a tool, just like Rust. If you don’t know how to use the tool, that’s not the tool’s fault.
You can always implement your own smart pointers. Besides that: which conventions do you mean?
Nah, although it has its persk, I just think that it also imposes a rigid framework that sometimes forces you into cumbersome workarounds. With C++, you retain full control over memory management and can choose the best tool for the job. You’re not boxed into a strict ownership model that may force refactoring or add extra layers of abstraction. Instead, you have a mature ecosystem with decades of evolution that lets you balance safety and control based on context. Sure, mistakes can happen, but with proper practices and modern C++ features you can achieve a level of safety that meets most needs without sacrificing the expressiveness and efficiency you might require in complex systems.
This is such a weird take. C++ isn’t memory safe. The blanket statement is… true. You say as much in the second sentence.
You have full control in Rust too, at least to the same extent as C++. Rust isn’t memory safe either. Rust is just the opposite of C++ in the approach to safety: you opt in to being unsafe with the
unsafeconstruct instead of being unsafe by default. They’re just different paradigms. I’d actually argue that you don’t have full control in either language unless you opt in to it, modern C++ tries very hard to abstract away memory management. You can write an entire program without a singlenewormalloc, which is pretty great.This is just simply not true and is consistently proven incorrect every time an aspect of C++'s memory unsafety is exploited. I work in security and I still, in 2025, exploit memory corruption. The best developers money can buy still make mistakes with C and C++.
The way you have to interact with smart pointers for example:
#include <memory> int main(int argc, char** argv) { std::unique_ptr<int> a = std::make_unique<int>(1); std::unique_ptr<int> b(a.get()); }Double free, but compiles without warning. It’s convention to not use
unique_pointer’s constructor, not enforced.#include <iostream> #include <string> int main(int argc, char** argv) { const char* c; { std::string a("HelloThisIsAHeapString"); c = a.c_str(); } std::cout << c << std::endl; }Use after free. No compiler error or warning, it’s convention to not maintain references to C++ string data, not enforced.
That’s all fine, whatever, but these are conventions. We’ve shot ourselves in the foot a million times and come up with our own guard rails, but the developer needs to know all of them to not make the mistake.
I suppose we need to make definitions clearer. C++ is memory safe in the sense that you can write memory safe code. It doesn’t enforce memory safety though. But not doing that is not the language’s fault. If someone jumps with a bike from a flying airplane, it’s not the bike’s fault that they will not land safely. It’s the misuse of the bike.
I’d argue those weren’t the best developers then. However, I don’t want to get ridiculous. I see that there are problems in the common use of C++. Although I can’t share that from my experience due to usually proper usage, thorough testing use of additional tools, there is surely a need for aiding C++ devs with writing safe code. I know of the corresponding security concerns as well as probably everyone else in the C++ community.
There are proposals to improve on that. Some of those might already come with C++26. Stroustrup’s favourite are Profiles to provide and enforce further guarantees, while others propsed an extension like Safe C++. Whereever the future will take us with C++, I’m confident that this issue will be sufficiently solved one day.
There was a time when C++ wasn’t even designed for multi-processor systems, lol. That was redesigned pretty late. Much has changed and it will continue to improve as C++ continues to mature.
Edit: Just saw your convention examples after I’ve sent my reply. Idk why it wasn’t displayed before.
Regarding the double free: It’s clear from the documentation that this returns a raw pointer.
Regarding the use after free:
I really don’t want to sound arrogant as this is a simple example of course, but that is such an obvious mistake and looks like a topic which is covered in C++ beginner classes. To me, this is almost on the same level as dividing by zero and wondering about resulting bugs.
Yes. Not every language is as user-friendly as python. With more flexibility come more risks but also more rewards if you’ve mastered it. It depends on what you want to do and how much you’re willing to invest. I would at least expect a professional dev to rtfm. Which itself is apparently already a problem. But, in the end of the day we want to use tools, which are effective and easy to use. So sure, point taken. I refer to the section before my edit regarding developments upon improving such aspects in C++.
sure, maybe, but performance doesn’t matter for deciding if a language is memory-safe or not. And C++ isn’t memory-safe by any commonly used interpretation of that word.
You may of course decide that the downsides of memory-safety aren’t worth it for your use-case, that is a separate issue
I think it boils down, how we define “memory safe”. C++ is perfectly memory safe, if you know what you’re doing. A lot of people don’t. Which is why Rust was born. that doesn’t make C++ a memory-unsafe language. It just demands more responsibility from the user. A design philosophy that comes with a lot more flexibility than Rust can offer.
Which is fine. Both languages have their perks. But saying C++ isn’t memory safe, while Rust is, is in my opinion just plainly wrong. Besides, with “unsafe” Rust inherently already the door for memory issues.
Modern C++ practises and dev patterns can handle most memory issues in C++ pretty easily. Consider smart pointers for example, or RAII.
It’s not the language’s fault if it is used wrong.
https://en.m.wikipedia.org/wiki/Memory_safety
https://www.memorysafety.org/docs/memory-safety/
https://media.defense.gov/2022/Nov/10/2003112742/-1/-1/0/CSI_SOFTWARE_MEMORY_SAFETY.PDF
https://www.cisa.gov/news-events/news/urgent-need-memory-safety-software-products
why do you want to redefine what the term means? why does it hurt to admit that C++ is not memory safe? It’s not about your weakness.
Which language would you say is not memory safe then? Is there any serious language out there where you should expect memory issues if you don’t make any mistakes?
If the standard is “you know what you’re doing and never make mistakes”, then all languages are memory safe. All you’re doing is arguing against memory safety as a concept by redefining the term in such a way that it becomes meaningless.
Every source I’ve seen has shown rust and c++ to be very similar in terms of performance.
It’s not just about runtime performance, but also about coding flexibility, and for example also reduction of boilerplate.
Ah yes, I love how C++ is has so little boilerplate. Sometimes I can even write several statements in a row without any!
The good news is that the browser comes from Serenity OS which means it probably is lightweight and well written.