Comments (6)
合法的,init(14, '*');
实际上是:init(14, 42, ' ');
, 省略的是 bckgrnd
, '*' 提升为 int
, 作为 wd.
check: http://coliru.stacked-crooked.com/a/520f55dd0ee62aa1
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我一直不是很理解“提升”这个词的意思,请问书里有提到这方面内容吗?我只能找到只言片语。不知道什么对于什么是提升,什么对于什么不是提升。
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我一直不是很理解“提升”这个词的意思
就是 Implicit Conversions
书里有提到这方面内容吗
当然有,4.11. Type Conversions 整个小结。
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4.11 当时也看不太懂,类型之间怎么比较大小呢?
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不同类型之间的比较分为两步:
- 类型的提升, 譬如 Integral Promotions,即,char 类型与 int 类型比较,char 类型会自动提升为 int。
- 同类型之间的比较,都是 int 类型了,再比较大小。
The types
bool
,char
,signed char
,unsigned char
,short
, andunsigned short
are promoted toint
if all possible values of that type fit in anint
.
Otherwise, the value is promoted tounsigned int
.
关键就在于第一步,类型的提升,说白了,就是小类型往大类型看齐。bool,char 之类向 int 看齐;float 向 double 看齐。
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明白了,谢谢!
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Related Issues (20)
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