Porting code written for old compiler to new compiler

Recently I installed newer version of Ubuntu Linux (20.04) and noticed it doesn't have GCC 6 anymore... I know my code compiled with GCC 7 already, but I was curious how much it would take to make it compile with GCC 8 or newer, and more recent versions of Clang.

GCC 7 to GCC 8

• Most important change is that for simple variable types, copying using memcpy() is now discouraged. Direct assignment should be used instead.

GCC 8 to GCC 9

• When returning a class that has same type as return type of a function, std::move() should not be explicitly used.

GCC 9 to GCC 10

• cstdint and stdexcept headers need to be explicitly included when using standard integer types or throwing run-time exceptions

GCC to Clang

• Clang use different options to disable warnings
  • For example -Wlogical-op and -Wno-maybe-uninitialized are not supported
• Clang requires explicit copy constructor if there is copy assignment operator
• Clang requires explicit move constructor if there is move assignment operator
• Clang requires explicit virtual destructor, if class has virtual methods
• Clang requires "override" keyword for virtual methods that override existing method in derived class