[MESOS-5471] Enable `Option` to handle string literals gracefully

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Labels: flags mesosphere
• Story Points: 2
• Assignee: Unassigned
• Reporter: Greg Mann
• Created: 27/May/16 09:30
• Updated: 27/May/16 09:30

Description

In FlagsBase::add, MESOS-5064 begins making use of template function parameters like T2* for the default flag value rather than Option<T2>&. This is because in some places in the code base, we pass string literals for this argument. If an Option type is used, the compiler infers a char [x] type for T2, which breaks Option::getOrElse, which attempts to return that same type, since returning arrays is disallowed.

To fix this, we could employ std::decay, which would convert a return type of char [x] into const char *.