PaulXiCao

Multiple functions in `autodiff/forward/real/real.hpp` are marked `constexpr` which does not align with the standard, e.g. `exp`, `pow`, ... This is a non-standard gcc extension, see [here](https://stackoverflow.com/q/27744079). Thus, the following example...

I am in the process of creating unit tests for files under `autodiff/common/` and came across unused functions. I removed it. Btw. `TupleTail` is not `constexpr` as discussed [here](https://stackoverflow.com/questions/59563997/why-is-constexpr-with-stdforward-as-tuple-not-working).

The binomial coefficients are hard-coded in `autodiff/common/binomialcoefficient.hpp` upto order 50. Their correctness is hard to verify. This data could be computed via some simple python script, e.g. using [`math.comp`](https://docs.python.org/3/library/math.html#math.comb) or...

Supply `MakeVanillaSwap` builder to `SwapRateHelper`

3

(Partially) Closes #1393 . This mr implements [the idea](https://github.com/lballabio/QuantLib/issues/1393#issuecomment-1955810263) from @eltoder to supply builders instead of adding more and more arguments to the constructors. I will add some inline comments...

[libc++][math] Fix undue overflowing of `std::hypot(x,y,z)`

2

Closes #92782. The 3-dimentionsional `std::hypot(x,y,z)` was sub-optimally implemented. This lead to possible over-/underflows in (intermediate) results which can be circumvented by this proposed change. The idea is to to scale...

Compiler errors after clippy fixes. Maybe issue with WebAssembly attribute.

2

### Summary I ran clippy on my code and it reported: "_after fixes were automatically applied the compiler reported errors within these files: ..._". My code is available at: https://github.com/PaulXiCao/oxidized-turret/commit/6ee2ffae90827dd871b46437ef7204c099625152....

There is an online workshop by google: https://google.github.io/comprehensive-rust/. We should find a place to link to it.

In the "People" section there are multiple links to rustaceans.org which is no longer maintained.

Closes #1495 .

Closes #1497. Updates the documentation to properly reflect the implementation that changes the input entries even when inversion fails (for matrix dimension `n>=5`). Changing implementation to uphold its current promise...