Using boost::replace_all: #include <boost/algorithm/string.hpp> // include Boost, a C++ library … std::string target(“Would you like a foo of chocolate. Two foos of chocolate?”); boost::replace_all(target, “foo”, “bar”);
The C++ standard library does not have one, but Boost.Range has boost::counting_range, which certainly qualifies. You could also use boost::irange, which is a bit more focused in scope. C++20’s range library will allow you to do this via view::iota(start, end).
There are two issues with rand() % 6 (the 1+ doesn’t affect either problem). First, as several answers have pointed out, if the low bits of rand() aren’t appropriately uniform, the result of the remainder operator is also not uniform. Second, if the number of distinct values produced by rand() is not a multiple of … Read more
The most pat answer would be that the C library has no corresponding “strtou”, and the C++11 string functions are all just thinly veiled wrappers around the C library functions: The std::sto* functions mirror strto*, and the std::to_string functions use sprintf. Edit: As KennyTM points out, both stoi and stol use strtol as the underlying … Read more
From the C++11 Standard (emphasis mine): D.5 C standard library headers [depr.c.headers] For compatibility with the C standard library … Every C header, each of which has a name of the form name.h, behaves as if each name placed in the standard library namespace by the corresponding cname header is placed within the global namespace … Read more
Every system call that fails update the errno value. Thus, you can have more information about what happens when a ifstream open fails by using something like : cerr << “Error: ” << strerror(errno); However, since every system call updates the global errno value, you may have issues in a multithreaded application, if another system … Read more
Note – You may also want to check other answers, especially the one with decltype and lambda You should declare a class Compare and overload operator() for it like this: class Foo { }; class Compare { public: bool operator() (Foo, Foo) { return true; } }; int main() { std::priority_queue<Foo, std::vector<Foo>, Compare> pq; return … Read more
If you have only 50 values in std::map you could copy them to std::vector before printing out and sort via std::sort using appropriate functor. Or you could use boost::multi_index. It allows to use several indexes. In your case it could look like the following: struct value_t { string s; int i; }; struct string_tag {}; … Read more
In short, use std::function unless you have a reason not to. Function pointers have the disadvantage of not being able to capture some context. You won’t be able to for example pass a lambda function as a callback which captures some context variables (but it will work if it doesn’t capture any). Calling a member … Read more
This is implementation dependent: Standard 23.1.2.8: The insert members shall not affect the validity of iterators and references to the container, and the erase members shall invalidate only iterators and references to the erased elements. Maybe you could try this — this is standard conforming: for (auto it = numbers.begin(); it != numbers.end(); ) { … Read more