std::basic_stacktrace - cppreference.com (original) (raw)
| Defined in header | ||
|---|---|---|
| template< class Allocator > class basic_stacktrace; | (1) | (since C++23) |
| using stacktrace = std::basic_stacktrace<std::allocator<std::stacktrace_entry>>; | (2) | (since C++23) |
| namespace pmr { using stacktrace = std::basic_stacktrace<std::pmr::polymorphic_allocator<std::stacktrace_entry>>; } | (3) | (since C++23) |
The
basic_stacktraceclass template represents a snapshot of the whole stacktrace or its given part. It satisfies the requirement of AllocatorAwareContainer, SequenceContainer, and ReversibleContainer, except that only move, assignment, swap, and operations for const-qualified sequence containers are supported, and the semantics of comparison functions are different from those required for a container.Convenience type alias for the
basic_stacktraceusing the default std::allocator.
The invocation sequence of the current evaluation \(\small{ {x}_{0} }\)x0 in the current thread of execution is a sequence \(\small{ ({x}_{0}, \dots, {x}_{n})}\)(x0, ..., xn) of evaluations such that, for \(\small{i \ge 0}\)i≥0, \(\small{ {x}_{i} }\)xi is within the function invocation \(\small{ {x}_{i+1} }\)xi+1.
A stacktrace is an approximate representation of an invocation sequence and consists of stacktrace entries.
A stacktrace entry represents an evaluation in a stacktrace. It is represented by std::stacktrace_entry in the C++ standard library.
Contents
- 1 Template parameters
- 2 Member types
- 3 Member functions
- 4 Non-member functions
- 5 Helper classes
- 6 Notes
- 7 Example
- 8 See also
[edit] Template parameters
| Allocator | - | An allocator that is used to acquire/release memory and to construct/destroy the elements in that memory. The type must meet the requirements of Allocator. The program is ill-formed if Allocator::value_type is not std::stacktrace_entry. |
|---|
[edit] Member types
| Member type | Definition |
|---|---|
| value_type | std::stacktrace_entry |
| const_reference | const value_type& |
| reference | value_type& |
| const_iterator | implementation-defined const LegacyRandomAccessIterator type that models random_access_iterator |
| iterator | const_iterator |
| reverse_iterator | std::reverse_iterator<iterator> |
| reverse_const_iterator | std::reverse_iterator<const_iterator> |
| difference_type | implementation-defined signed integer type |
| size_type | implementation-defined unsigned integer type |
| allocator_type | Allocator |
[edit] Member functions
| (constructor) | creates a new basic_stacktrace (public member function) [edit] |
|---|---|
| (destructor) | destroys the basic_stacktrace (public member function) [edit] |
| operator= | assigns to the basic_stacktrace (public member function) [edit] |
| current[static] | obtains the current stacktrace or its given part (public static member function) [edit] |
| get_allocator | returns the associated allocator (public member function) [edit] |
| Iterators | |
| begincbegin | returns an iterator to the beginning (public member function) [edit] |
| endcend | returns an iterator to the end (public member function) [edit] |
| rbegincrbegin | returns a reverse iterator to the beginning (public member function) [edit] |
| rendcrend | returns a reverse iterator to the end (public member function) [edit] |
| Capacity | |
| empty | checks whether the basic_stacktrace is empty (public member function) [edit] |
| size | returns the number of stacktrace entries (public member function) [edit] |
| max_size | returns the maximum possible number of stacktrace entries (public member function) [edit] |
| Element access | |
| operator[] | access specified stacktrace entry (public member function) [edit] |
| at | access specified stacktrace entry with bounds checking (public member function) [edit] |
| Modifiers | |
| swap | swaps the contents (public member function) [edit] |
[edit] Non-member functions
[edit] Helper classes
[edit] Notes
Support for custom allocators is provided for using basic_stacktrace on a hot path or in embedded environments. Users can allocate stacktrace_entry objects on the stack or in some other place, where appropriate.
The sequence of std::stacktrace_entry objects owned by a std::basic_stacktrace is immutable, and either is empty or represents a contiguous interval of the whole stacktrace.
boost::stacktrace::basic_stacktrace (available in Boost.Stacktrace) can be used instead when std::basic_stacktrace is not available.
| Feature-test macro | Value | Std | Feature |
|---|---|---|---|
| __cpp_lib_stacktrace | 202011L | (C++23) | Stacktrace library |
| __cpp_lib_formatters | 202302L | (C++23) | Formatting std::thread::id and std::stacktrace |
[edit] Example
The output obtained using Compiler Explorer: msvc and gcc.
#include #include int nested_func(int c) { std::cout << std::stacktrace::current() << '\n'; return c + 1; } int func(int b) { return nested_func(b + 1); } int main() { std::cout << func(777); }
Possible output:
// msvc output (the lines ending with '⤶' arrows are split to fit the width): 0> C:\Users\ContainerAdministrator\AppData\Local\Temp\compiler-explorer-compiler20221122-⤶ 31624-2ja1sf.8ytzw\example.cpp(6): output_s!nested_func+0x1F 1> C:\Users\ContainerAdministrator\AppData\Local\Temp\compiler-explorer-compiler20221122-⤶ 31624-2ja1sf.8ytzw\example.cpp(12): output_s!func+0x15 2> C:\Users\ContainerAdministrator\AppData\Local\Temp\compiler-explorer-compiler20221122-⤶ 31624-2ja1sf.8ytzw\example.cpp(15): output_s!main+0xE 3> D:\a_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl(288): output_s!⤶ __scrt_common_main_seh+0x10C 4> KERNEL32!BaseThreadInitThunk+0x14 5> ntdll!RtlUserThreadStart+0x21 779 gcc output: 0# nested_func(int) at /app/example.cpp:7 1# func(int) at /app/example.cpp:13 2# at /app/example.cpp:18 3# at :0 4# at :0 5# 779