AS::Map function improvement

[hanton]

1. Prefer using reserve function rather than fill constructor in AS::map() for memory efficiency

fill constructor constructs the vector with n elements and initializes each element with its default constructor, while reserve function just allocates memory, 0 element is need to be initialized.

For example, after running result_type res(iterable.size());, the res vector's size is equal to iterable.size(), while after running res.reserve(iterable.size());, the res vector's size is 0.

Reference:

• http://www.cplusplus.com/reference/vector/vector/vector
• http://www.cplusplus.com/reference/vector/vector/reserve
• http://www.cplusplus.com/reference/iterator/back_inserter

2. Add tests for ASLayoutSpecUtilities

[matthewd1234]

K

[vovasty]

Hi @hanton, could you please resolve merging conflicts, so we can merge you PR?

[hanton]

Hi @hanton, could you please resolve merging conflicts, so we can merge you PR?

hi @vovasty ,merge conflicts are solved, but CI fails because of this error:

** BUILD FAILED **
The following build commands failed:
	CompileAssetCatalog /Users/runner/ASDKDerivedData/Build/Products/Debug-iphonesimulator/Sample.app /Users/runner/runners/2.159.1/work/Texture/Texture/examples/CustomCollectionView-Swift/Sample/Assets.xcassets
(1 failure)

However, in my local build ./build.sh examples-pt1, it shows Build Succeeded.