vcpkg#81

Draft

michaelkirk wants to merge 3 commits intomainfrom

Commits on Mar 3, 2021

add support of vcpkg with msvc toolchain
Vincent PRELAT
committed

Commits on Mar 12, 2021

add CI msvc

Vincent PRELAT
authored and
lapoigne
committed
test assert_relative_eq, add epsilon for small changes in grid
lapoigne
committed