* format-inl.h(444,1): warning C4804: '>>': unsafe use of type 'bool' in operation
format.h(2808,1): warning C4127: conditional expression is constant
* More fixes for VS2019 pedantic warnings
* Fix "conditional expression is constant" VS2019 warning in more specific way
* Use const_check to silence constexpr warning
If you compile using `nvcc` and pass the option `--expt-relaxed-constexpr` it will crash with an internal compiler error. This modification prevents using `constexpr` in `fmtlib` when compiling using `nvcc` and prevents the crash.
* Avoid weak vtables by providing a private virtual member function
* Add warning Wweak-vtables to clang when FMT_PEDANTIC is on
* Add defaulted copy and move operations to format_error and system_error
Compiler generated copy operations are deprecated and move operations
are not generated altogether.
* Add warning Wdeprecated to clang when FMT_PEDANTIC is on
When `MoveCtor` performs `check_move_buffer`, the buffer allocator becomes null,
but then `MoveCtor` attempts to use it to allocate a dynamic buffer. This
succeeds nevertheless because a typical `std::allocator<char>::allocate` does
not use `this`, so it does not crash when `this` is null.
Fixes#1344
* Fix undefined in core-test
Fixes "reference binding to null pointer" in BufferTest.Ctor
buffer.operator[] attempts to return a reference to `buffer.ptr_[0]` when `ptr_`
in `mock_buffer<int> buffer` is null.
* Fix undefined in printf-test
Fixes "signed integer overflow" in PrintfTest.Length
This occurs in `TestLength<long long>("ll")`, since its minimum value minus one
does not fit in long long.
* Fix undefined in printf %0$
Printf counts arguments from 1.
Fixes "shift exponent -4 is negative" in PrintfTest.InvalidArgIndex.
`do_get` is called with index -1 when `basic_printf_context.arg` is called with
id 4294967295 when basic_printf_context::get_arg subtracts 1 from arg_index 0 in
the format string "%0$d".
