tree 3fa20e0782c80d34527211585a13ebac0a67cc33
parent b01a5b4fce9ecab463541f180c4297ce166e2c5d
author Patrick Williams <patrick@stwcx.xyz> 1630181909 -0500
committer Patrick Williams <patrick@stwcx.xyz> 1630360489 +0000

lg2: fix clang static_assert fire

There are variants of the conversion functions that are in place
simply to provide better diagnostics to users when they pass the
wrong content into a `lg2::log` function.  Most of these use
`static_assert`s which can only fire when the compiler is able to
deduce the appropriate types, and thus the function is incorrectly
being used.

clang happens to be smarter than that.  Even when it cannot deduce
the types necessary to fully instantiate the function, the asserts
can fire if all of the types necessary for the `static_assert` were
deduced.  Thus a `static_assert` like this can trigger:

    static_assert(!std::is_same<foo, foo>, ...)

Workaround this by ensuring that at least one un-deduced type is
included in all of these diagnostic-function-only `static_assert`.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I025e08661c6250c886803dfc308ad6acbd7e57cb