[lmi] Compiler diagnostics [Was: master 6a59da54 8/8: When in doubt, prefer the Rule of Five to the Rule of Zero]

[Greg Chicares]

On 7/11/22 16:22, Greg Chicares wrote:
[...]
> Experimentally, for Rule of 0-->5 changes, I copied the old dtor that I
> had removed, and added the other four members, all deleted; then I did
> s/delete/default/ as few times as possible to get everything to build.

BTW, I just wanted to mention how difficult that process can be.
For example, if we change 'fund_data.hpp' thus:

-    FundInfo(FundInfo const&) = default;
+    FundInfo(FundInfo const&) = delete;

then clang's diagnostics are about thirty lines long, and only
one of those lines says that a ctor has been deleted, without
saying which one:

/usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/stl_construct.h:94:5:
 note: candidate template ignored: substitution failure [with _Tp = FundInfo, 
_Args = <const FundInfo &>]: call to deleted constructor of 'FundInfo'

OTOH, gcc issues more lines of diagnostics than clang, but
does identify the cause directly:

/opt/lmi/src/lmi/fund_data.hpp:51:5: note: declared here
   51 |     FundInfo(FundInfo const&) = delete;

Some years ago, clang's diagnostics were generally better than
gcc's, but now neither one seems much better than the other.

Should I hope for better clang diagnostics if I use its
  https://libcxx.llvm.org/
standard library?