Re: [boost] Environment Variables Library?

The C runtime getenv/_putenv functions actually maintain two separate copies of the environment, one narrow, one wide.

https://msdn.microsoft.com/en-us/library/tehxacec.aspx

... and those appear to be distinct from the OS environment block that SetEnvironmentVariable modifies. So that makes three (or maybe four) copies in total. It's fun for the whole family.