C++ Error Messages

The C++ language, standard library and compilers.All C++ pages

C++ error: 'x' was not declared in this scopeGCC cannot find the name at that point: a missing #include, a missing std:: prefix, a function used before its declaration, or a variable outside its block.
C++ error: no matching function for call toNo candidate function, constructor or template accepts the argument types you passed. Read the candidate notes, then fix the arguments, overloads or types.
C++ undefined reference to `function()' (ld returned 1 exit status)undefined reference is a linker error: a function was declared but its definition was not linked. Add the .cpp file or library, fix -l order, or define it.
C++: error: no member named 'setw' in namespace 'std' (gcc: 'setw' is not a member of 'std')Clang no member named 'X' in namespace 'std' (GCC: not a member of 'std') means its header is not included or -std is too old. Add the include, set -std=c++20.