原来格式为表格（table），转换较复杂，未转换，需要手动复制一下
{"cells":[{"textAlign":"left","verticalAlign":"top","wrap":true,"backColor":"rgb(85, 85, 85)","value":"限定符"},{"textAlign":"left","verticalAlign":"top","wrap":true,"backColor":"rgb(85, 85, 85)","value":"含义"},{"textAlign":"left","verticalAlign":"top","wrap":true,"value":"const"},{"textAlign":"left","verticalAlign":"top","wrap":true,"value":"const 类型的对象在程序执行期间不能被修改改变。","inlineStyles":{"bold":[{"from":0,"to":5,"value":true}]}},{"textAlign":"left","verticalAlign":"top","wrap":true,"backColor":"rgb(246, 244, 240)","value":"volatile"},{"textAlign":"left","verticalAlign":"top","wrap":true,"backColor":"rgb(246, 244, 240)","value":"修饰符 volatile 告诉编译器不需要优化volatile声明的变量，让程序可以直接从内存中读取变量。对于一般的变量编译器会对变量进行优化，将内存中的变量值放在寄存器中以加快读写效率。","inlineStyles":{"bold":[{"from":4,"to":12,"value":true}]}},{"textAlign":"left","verticalAlign":"top","wrap":true,"value":"restrict"},{"textAlign":"left","verticalAlign":"top","wrap":true,"value":"由 restrict 修饰的指针是唯一一种访问它所指向的对象的方式。只有 C99 增加了新的类型限定符 restrict。","inlineStyles":{"bold":[{"from":2,"to":10,"value":true}]}}],"heights":[40,40,40,40],"widths":[81,753]}

变量可见域与生命周期

static

静态全局变量：全局变量默认有外部链接性，可以在其他文件通过extern调用，而静态全局变量的作用域只在本文件
静态局部变量：存储在全局数据区，生存周期和程序一致，声明时会被自动初始化为0
静态函数：作用域只在本文件
类的静态成员函数：

extern

register

thread_local

mutable

auto