SOVERSION bump required

[roehling]

I noticed that the SOVERSION is still at 1 even though each release introduces binary incompatibilities. Unfortunately C++ is very picky with its binary interface, so seemingly harmless changes that are source code compatible can break binary compatibility.

For instance, going from rc5 to rc6 introduced the change from typedef struct _material_t ... material_t to struct material_t that changes the exported symbols for all functions taking material_t parameters, but the SOVERSION was not bumped.

It would be nice if at least the full releases would manage that change properly, because it makes it much simpler to package the library in a Linux distribution.

[syoyo]

TinyObjLoader is header-only library and we basically do not recommend to distribute tinyobjloader as a binary package.

Anyway, bumping SOVERSION should be easy.
What is best way to specify SOVERSION for Windows/macOS/Linux ?

Although semantic versioning allows -rc tag https://semver.org/, I'm not sure it is possible to add such a tag to SOVERSION. For example:

set(TINYOBJLOADER_SOVERSION "2.0.0-rc.6")

[roehling]

Actually, the SOVERSION can be just about anything. It is common to count up an integer whenever the ABI changes. If maintaining a stable ABI over multiple releases is not a priority, you can also just set the SOVERSION to the actual version number.

[syoyo]

After some web searches, it looks its common to use major version number for SOVERSION, so I have bumped it to 2

[roehling]

I'm hijacking this issue for a follow-up question, mainly out of curiosity: what are your plans regarding the finalized 2.0.0 release? I've seen several projects migrate to the release candidates now, so there is clearly some interest.

[syoyo]

@roehling As far as I know there should be no critical issues in v2.0.0 RC version so I think its mostly ready to release v2.0.0, after finishing full or nearly full python binding #207 and some code/API cleanups. I cannot promise when we can releasev2.0.0, but probably by Spring 2021.