tree 4b475139de99ceb99b4b3f7bf5971768ddc8f195
parent 87b6a8d331867c24f7bd5f0160199478d97383b0
author Patrick Williams <patrick@stwcx.xyz> 1626446951 -0500
committer Patrick Williams <patrick@stwcx.xyz> 1626450022 -0500

message: correctly unpack variants of enums

When a variant contains multiple types which can be converted
from a string (such as two enums, or an enum and string), the
previous code tried a conversion from the first type in the
variant.  When the first type was an enum, this often threw an
exception.  When the first type was a string, this turned into
a plain string containing the dbus enum value.

Add special cases to the variant unpacking to detect types
which are convertible from strings and delegate to a template
specialization of 'convert_from_string' which handles variants.
This specialization will attempt all conversions first and then
revert to a string as a fallback.

Fixes openbmc/sdbusplus#52.

Change-Id: Ide5a0030d595fbaf01122fa8a0ecdaa19ad0078c
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>