implement FieldValue for null, boolean, and array in C++.#637

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zxu123 merged 8 commits intomasterfrom

Jan 17, 2018

Commits on Jan 10, 2018

implement FieldValue for null and boolean.
zxu123
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Commits on Jan 11, 2018

refactoring to use union type instead of poly
zxu123
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Commits on Jan 12, 2018

refactor using union design intead of poly
zxu123
committed

Commits on Jan 13, 2018

refactoring to use anonymous union and fix styles
zxu123
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