Open vs. Closed Constructed Generic Types: What's the Difference?

C folderexpressions is a feature introduced by C 17 to simplify recursive operations in variadic parameter templates. 1. Left fold (args...) sum from left to right, such as sum(1,2,3,4,5) returns 15; 2. Logical and (args&&...) determine whether all parameters are true, and empty packets return true; 3. Use (std::cout

If it is iterating when deleting an element, you must avoid using a failed iterator. ①The correct way is to use it=vec.erase(it), and use the valid iterator returned by erase to continue traversing; ② The recommended "erase-remove" idiom for batch deletion: vec.erase(std::remove_if(vec.begin(),vec.end(), condition), vec.end()), which is safe and efficient; ③ You can use a reverse iterator to delete from back to front, the logic is clear, but you need to pay attention to the condition direction. Conclusion: Always update the iterator with the erase return value, prohibiting operations on the failed iterator, otherwise undefined behavior will result.

The answer is: Use the std::string constructor to convert the char array to std::string. If the array contains the intermediate '\0', the length must be specified. 1. For C-style strings ending with '\0', use std::stringstr(charArray); to complete the conversion; 2. If the char array contains the middle '\0' but needs to convert the first N characters, use std::stringstr(charArray,length); to clearly specify the length; 3. When processing a fixed-size array, make sure it ends with '\0' and then convert it; 4. Use str.assign(charArray,charArray strl

TheautokeywordinC deducesthetypeofavariablefromitsinitializer,makingcodecleanerandmoremaintainable.1.Itreducesverbosity,especiallywithcomplextypeslikeiterators.2.Itenhancesmaintainabilitybyautomaticallyadaptingtotypechanges.3.Itisnecessaryforunnamed

Use std::source_location::current() as the default parameter to automatically capture the file name, line number and function name of the call point; 2. You can simplify log calls through macros such as #defineLOG(msg)log(msg,std::source_location::current()); 3. You can expand the log content with log level, timestamp and other information; 4. To optimize performance, function names can be omitted or location information can be disabled in the release version; 5. Column() and other details are rarely used, but are available. Using std::source_location can significantly improve the debugging value of logs with extremely low overhead without manually passing in FIL

ABinarySearchTree(BST)isabinarytreewheretheleftsubtreecontainsonlynodeswithvalueslessthanthenode’svalue,therightsubtreecontainsonlynodeswithvaluesgreaterthanthenode’svalue,andbothsubtreesmustalsobeBSTs;1.TheC implementationincludesaTreeNodestructure

std::mutex is used to protect shared resources to prevent data competition. In the example, the automatic locking and unlocking of std::lock_guard is used to ensure multi-thread safety; 1. Using std::mutex and std::lock_guard can avoid the abnormal risks brought by manual management of locks; 2. Shared variables such as counters must be protected with mutex when modifying multi-threads; 3. RAII-style lock management is recommended to ensure exception safety; 4. Avoid deadlocks and multiple locks in a fixed order; 5. Any scenario of multi-thread access to shared resources should use mutex synchronization, and the final program correctly outputs Expected:10000 and Actual:10000.

The most common method of finding vector elements in C is to use std::find. 1. Use std::find to search with the iterator range and target value. By comparing whether the returned iterator is equal to end(), we can judge whether it is found; 2. For custom types or complex conditions, std::find_if should be used and predicate functions or lambda expressions should be passed; 3. When searching for standard types such as strings, you can directly pass the target string; 4. The complexity of each search is O(n), which is suitable for small-scale data. For frequent searches, you should consider using std::set or std::unordered_set. This method is simple, effective and widely applicable to various search scenarios.