I encounter a problem in opennurbs_lock.h when building in Visual Studio 2019 using Intel C++ Compiler 2021. The error occurs due to line 118 and is reported as:
copying member subobject of type 'std::atomic<int>' invokes deleted constructor
It builds without error by changing line 118 in opennurbs_lock.h from:
std::atomic<int> m_lock_value = ON_Lock::UnlockedValue;
to:
std::atomic<int> m_lock_value = { ON_Lock::UnlockedValue };