Implements:
- P2291R3 Add Constexpr Modifiers to Functions to_chars and from_chars for
Integral Types in <charconv> Header
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D131317
Implementing the paper
P2291R3 Add Constexpr Modifiers to Functions to_chars and from_chars for
Integral Types in <charconv> Header
Gives issues in language versions prior to C++17. As suggested in
D131855 disable the code prior to C++17. This removes libc++'s
extension.
Reviewed By: ldionne, #libc_vendors, #libc, philnik
Differential Revision: https://reviews.llvm.org/D133216
This is required by the Standard and makes it possible to add full
128-bit support to format.
The patch also fixes 128-bit from_chars "support". One unit test
required a too large value, this failed on 128-bit; the fix was to add
more characters to the input.
Note only base 10 has been optimized. Other bases can be optimized.
Note the 128-bit lookup table could be made smaller. This will be done later. I
really want to get 128-bit working in to_chars and format in the upcomming
LLVM 15 release, these optimizations aren't critical.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D128929
This was noticed in the review of D125704. In that commit only the new
table has been adapted. This adapts the existing tables.
Note since libc++'s charconv is backported to C++11 it's not possible to
use inline constexpr variables. The were introduced in C++17.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D126887
The functions to_chars and from_chars should offer 128-bit support. This
is the first step to implement 128-bit version of to_chars. Before
implementing 128-bit support the current code will be polished.
This moves the code from the dylib to the header in prepartion of
P2291 "Add Constexpr Modifiers to Functions to_chars and from_chars for
Integral Types in <charconv> Header"
Note some more cleanups will be done in follow-up commits
- Remove the _LIBCPP_AVAILABILITY_TO_CHARS from to_chars. With all code
in the header the availablilty macro is no longer needed. This
requires enabling the unit tests for additional platforms.
- The code in the dylib can switch to using the header implementation.
This allows removing the code duplicated in the header and the dylib.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D125704
Mark de Wever