Remove whitespace in literal operator declarations

[pps83]

Fixes this warning from clang:

In file included from D:/src/test.cpp:6:
D:/src/intx/include/intx/intx.hpp:1622:1: warning: identifier '_u128' preceded by whitespace in a literal operator declaration is deprecated [-Wdeprecated-literal-operator]
 1622 | DEFINE_ALIAS_AND_LITERAL(128);
      | ^
D:/src/intx/include/intx/intx.hpp:1617:34: note: expanded from macro 'DEFINE_ALIAS_AND_LITERAL'
 1617 |     consteval uint##N operator"" _u##N(const char* s) \
      |                                  ^
<scratch space>:168:1: note: expanded from here
  168 | _u128

[pps83]

fyi, pr for a similar fix for msvc's new preoprocessor in boost::mp boostorg/multiprecision#667

[chfast]

Do we need two levels of these JOIN macros?

[pps83]

Do we need two levels of these JOIN macros?

I didn't make it that way because I was bored :) At first I took whatever was from boost, and their join is 3-step nowadays:

#define BOOST_JOIN(X, Y) BOOST_DO_JOIN(X, Y)
#define BOOST_DO_JOIN(X, Y) BOOST_DO_JOIN2(X,Y)
#define BOOST_DO_JOIN2(X, Y) X##Y

whatever I did, I couldn't make it with 1 or 2 defines. I was already convinced that there was no way to avoid the warning in the first place, but then figured out what makes msvc happy.

[pps83]

did a bit more tinkering, and just got rid of one join

[chfast]

Suggested change

	consteval uint##N INTX_LITERAL(N)(const char* s) \
	consteval uint##N INTX_JOIN(operator"", _u##N)(const char* s) \

will this work?

[pps83]

yes, works. pr updated

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[chfast]

This is awesome, thanks very much for solving this issue.

[JasonCoombs]

Looking at this and trying to determine if my build is using the new commit or if it's building the older code in Hunter.

On MacOS with clang seeing this error from DEFINE_ALIAS_AND_LITERAL(128):

/Users/jason/intx/test/unittests/test_div.cpp:58:34: error: constexpr variable 'div_test_cases' must be initialized by a constant expression
   58 | constexpr div_test_case<uint512> div_test_cases[] = {
      |                                  ^                  ~
   59 |     {2, 1, 2, 0},
      |     ~~~~~~~~~~~~~
   60 |     {
      |     ~
   61 |         0x10000000000000000_u512,
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~
   62 |         2,
      |         ~~
   63 |         0x8000000000000000_u512,
      |         ~~~~~~~~~~~~~~~~~~~~~~~~
   64 |         0,
      |         ~~
   65 |     },
      |     ~~
   66 |     {
      |     ~
   67 |         0x7000000000000000,
      |         ~~~~~~~~~~~~~~~~~~~
   68 |         0x8000000000000000,
      |         ~~~~~~~~~~~~~~~~~~~
   69 |         0,
      |         ~~
   70 |         0x7000000000000000,
      |         ~~~~~~~~~~~~~~~~~~~
   71 |     },
      |     ~~
   72 |     {
      |     ~
   73 |         0x8000000000000000,
      |         ~~~~~~~~~~~~~~~~~~~
/Users/jason/intx/include/intx/intx.hpp:807:13: note: constexpr evaluation hit maximum step limit; possible infinite loop?
  807 |             x = (x << uint64_t{4}) | from_hex_digit(c);
      |             ^
/Users/jason/intx/include/intx/intx.hpp:1623:1: note: in call to 'from_string<intx::uint<128>>(&"0x800000000000007fc000000000007f80"[0])'
 1623 | DEFINE_ALIAS_AND_LITERAL(128);
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/jason/intx/include/intx/intx.hpp:1620:16: note: expanded from macro 'DEFINE_ALIAS_AND_LITERAL'
 1620 |         return from_string<uint##N>(s);                           \
      |                ^~~~~~~~~~~~~~~~~~~~~~~
/Users/jason/intx/test/unittests/test_div.cpp:308:9: note: in call to 'operator""_u128(&"0x800000000000007fc000000000007f80"[0])'
  308 |         0x800000000000007fc000000000007f80_u128,
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Documentation: https://clang.llvm.org/docs/UsersManual.html#controlling-implementation-limits

[JasonCoombs]

I don't understand why the template instantiation hits this limit, but it apparently does when building with clang on MacOS.

-fconstexpr-steps=N
Sets the limit for the number of full-expressions evaluated in a single constant expression evaluation. This also controls the maximum size of array and dynamic array allocation that can be constant evaluated. The default is 1048576.

See: https://clang.llvm.org/docs/UsersManual.html#controlling-implementation-limits

I added this to CMakeLists.txt and the build succeeded. Can't tell if this is newly-introduced behaviour with this commit, I am new here.

add_compile_options("-fconstexpr-depth=4096" "-fconstexpr-steps=4000000")

[chfast]

This is different issue. Quick fix is to change constexpr to static at the div_test_cases.