Looking for an easy way to reinitialize a struct

问题

I have a struct called CoolStruct:

struct CoolStruct

{
    int id;
    uint32 type;
    uint32 subtype;
    String name;
};

I have a vector of these structs as well:

std::vector<CoolStruct> coolVector;

I want to create a bunch of structs which have predefined values to push_back into this coolVector. I'd like to keep the code from getting cludgy and ugly. I would really like to keep this notation:

CoolStruct t = {1, EQData::EQ_EFFECT_TYPE_PARAMETRIC, 0, T("Parametric")};
coolVector.push_back(t);
CoolStruct t =  {2, EQData::EQ_EFFECT_TYPE_FILTER_LOW_PASS,EQData::EQ_FILTER_TYPE_FILTER_BUTTERWORTH_12DB, T("Low Pass")};
coolVector.push_back(t);

But of course this doesn't work... Not allowed to do a reinitialization. Is there any other solution to make this as readable as possible? The only alternative I can think of is it manually set each paramater of the struct:

t.id = whatever; t.type = somethingelse; t.subtype = thisisalotofcode; t.name = justtosetupthisvector;
coolVector.push_back(t);

回答1:

how about:

CoolStruct t1 = {1, EQData::EQ_EFFECT_TYPE_PARAMETRIC, 0, T("Parametric")};
coolVector.push_back(t1);
CoolStruct t2 = {2, EQData::EQ_EFFECT_TYPE_FILTER_LOW_PASS,EQData::EQ_FILTER_TYPE_FILTER_BUTTERWORTH_12DB, T("Low Pass")};
coolVector.push_back(t2);

In C++0x, I think you should be able to do:

CoolStruct t;
t = {1, EQData::EQ_EFFECT_TYPE_PARAMETRIC, 0, T("Parametric")};
coolVector.push_back(t);
t = {2, EQData::EQ_EFFECT_TYPE_FILTER_LOW_PASS,EQData::EQ_FILTER_TYPE_FILTER_BUTTERWORTH_12DB, T("Low Pass")};
coolVector.push_back(t);

or even:

coolVector.push_back({1, EQData::EQ_EFFECT_TYPE_PARAMETRIC, 0, T("Parametric")});
coolVector.push_back({2, EQData::EQ_EFFECT_TYPE_FILTER_LOW_PASS,EQData::EQ_FILTER_TYPE_FILTER_BUTTERWORTH_12DB, T("Low Pass")});

In fact, if you really want to get creative (and you don't have any previous elements that you want to keep), you can replace the whole vector with this syntax:

coolVector = {
   {1, EQData::EQ_EFFECT_TYPE_PARAMETRIC, 0, T("Parametric")},
   {2, EQData::EQ_EFFECT_TYPE_FILTER_LOW_PASS,EQData::EQ_FILTER_TYPE_FILTER_BUTTERWORTH_12DB, T("Low Pass")}
};

回答2:

if you add a simple constructor:

struct CoolStruct
{
    CoolStruct(int id, uint32 type, uint32 subtype, String name) : id(id), type(type), subtype(subtype), name(name) {}
    int id;
    uint32 type;
    uint32 subtype;
    String name;
};

you can then do this:

CoolVector.push_back(CoolStruct(1, EQData::EQ_EFFECT_TYPE_PARAMETRIC, 0, T("Parametric")));
CoolVector.push_back(CoolStruct(2, EQData::EQ_EFFECT_TYPE_FILTER_LOW_PASS,EQData::EQ_FILTER_TYPE_FILTER_BUTTERWORTH_12DB, T("Low Pass")));

来源：https://stackoverflow.com/questions/6684968/looking-for-an-easy-way-to-reinitialize-a-struct

标签

c++

struct

initialization