Item 7 : why not specialize function templates 條款7 :為什么不特化函數(shù)模板?
A function template is like an extension to a user - defined function 函數(shù)模板就像是用戶定義函數(shù)的一個擴展。
For the create function statement extension for function templates , refer to the 要了解函數(shù)模板的create function語句擴展,請參閱
Shows the issues to consider in determining when a function template needs to be registered 展示了在決定何時需要注冊函數(shù)模板時所考慮的問題。
When a query references a function template , the query optimizer tries to generate a feasible plan that allows this function reference to be evaluated on the remote data source 當(dāng)一個查詢引用一個函數(shù)模板時,查詢優(yōu)化器嘗試生成一個靈活的計劃,允許在遠(yuǎn)程數(shù)據(jù)源上計算這個函數(shù)引用。
If there is some special function specific to a data source and not available on websphere information integrator , you need a function template definition for that function 如果存在特定于某個數(shù)據(jù)源的、在websphere information integrator上沒有的特殊函數(shù),則需要那個函數(shù)的函數(shù)模板定義。
For functions , function templates , objects , and values , the library clauses specify declarations . implementations shall supply definitions consistent with the descriptions in the library clauses 對于函數(shù),函數(shù)模板,對象和值,庫條款規(guī)定了它們的聲明。實現(xiàn)應(yīng)該提供與庫條款的描述一致的定義。
For functions , function templates , objects , and values , the library clauses specify declarations . implementations shall supply definitions consistent with the descriptions in the library clauses 對于函數(shù),函數(shù)模板,對象和值,庫章節(jié)規(guī)定了它們的聲明。每個實現(xiàn)都應(yīng)該提供與標(biāo)準(zhǔn)庫章節(jié)的描述一致的定義。
For functions , function templates , objects , and values , the library clauses specify declarations . implementations shall supply definitions consistent with the descriptions in the library clauses 對于函數(shù),函數(shù)模板,對象和值,標(biāo)準(zhǔn)庫章節(jié)規(guī)定了它們的聲明。每個實現(xiàn)都應(yīng)該提供與標(biāo)準(zhǔn)庫章節(jié)的描述一致的定義。