to_string test fails about cppad

[bradbell]

Using the following system:
cppad.git>lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 18.04.2 LTS
Release: 18.04
Codename: bionic
cppad.git>g++ --version
g++ (Ubuntu 7.4.0-1ubuntu1~18.04) 7.4.0

I also got an error in the to_string test.
Starting in the top soruce directory and using the commands:
rm -rf build
mkdir build
cd build
cmake -D cppad_debug_which=debug_none ..
make check_example_utility

When I changed from debug_none to debug_all, I did not get the errror.

[bradbell]

If I insert the following print
std::cout << "max = " << max << ", check = " << check << "\n";
before line 54 in the file example/utility/to_string.cpp; just before
ok &= max == check;
The test passes. Do you get the same result ?

[bradbell]

I have submitted a Ubuntu g++ but report for this issue; see
https://bugs.launchpad.net/ubuntu/+source/gcc-defaults/+bug/1832132

[bradbell]

I think this is a gcc problem because it reproduces on Fedora 33 with
g++ (GCC) 10.2.1 20201125 (Red Hat 10.2.1-9)

In addition, the only compiler flag that is necessary to demonstrate the bug is '-O3' (on my Fedora 33 system). Any other level of optimization passes the test.

[bradbell]

It turns out it was an error in my test; see
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98151

I have made the corresponding fix to the test; see
9c2e69f

[bradbell]

@mkatliar Please close this issue if the current version works for you.