boost库的常用用法

class Shape
class Triangle : public Shape

1.shared_ptr
定义类：

typedef boost::shared_ptr<class Shape> ShapeSharedPtr;

实例化：

ShapeSharedPtr shapeSP = ShapeSharedPtr(new Shape());

定义数组：

typedef boost::shared_ptr<std::vector<ShapeSharedPtr>> ShapeListSharedPtr;

辅助定义：

typedef std::vector<boost::shared_ptr<class Shape>> ShapeList;

实例化 :

ShapeListSharedPtr shapeListSP = ShapeListSharedPtr(new ShapeList);

得到普通指针

Shape* pShape = shapeSP.get();

普通指针封装

Shape* shapePointer = new Shape();
ShapeListSharedPtr shapePointerSP = ShapeListSharedPtr(shapePointer);

主动释放：

shapeSP.reset();

2.dynamic_pointer_cast

typedef boost::shared_ptr<class Triangle> TriangleSharedPtr;

ShapeSharedPtr triangleShapeSP = ShapeSharedPtr(new Triangle());

TriangleSharedPtr triangleSP = boost::dynamic_pointer_cast<Traingle>(
triangleShapeSP);

if(trangleSP.get())
{
//为子类对象
}

3.lexical_cast
基本类型转换

String strNum = "3.1415926";
try
{
    int nNum = boost::lexical_cast<int>(strNum);
}catch(boost::bad_lexical_cast e)
{
//转换失败
}