sizeof string?

Code:

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#include <iostream>
#include <string>
using namespace std;

int main() {
        std::string s1 = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
        std::string s2 = "a";
        cout << sizeof(s1) << endl;
        cout << sizeof(s2) << endl;
        cin.get();
}

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Why does sizeof give me 32 for both strings?

Why shouldn't it? sizeof is not .size(), after all.

>Why does sizeof give me 32 for both strings?
What you're looking for is s1.length() or s1.size(). sizeof gives you the sizeof the data structure, in this case the size of the string class. For example (sizeof int) would tell you how many bytes an int is on your system. Or cout << std::numeric_limits<int>::max() would print the maximum value an int can contain.

strlen()

Quote:

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strlen()

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No. strlen() is for C-strings (char *, not std::string).

I actually saw some developers at a previous job use:

Code:

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strlen( something.c_str() );

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Luckily I was on the other side of the building when I was reviewing the code, so they couldn't hear me laughing my ass off. :)

Quote:

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Originally Posted by cpjust

I actually saw some developers at a previous job use:

Code:

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strlen( something.c_str() );

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Luckily I was on the other side of the building when I was reviewing the code, so they couldn't hear me laughing my ass off. :)

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Looks like they learned C++ using Visual Studio 7 or something. If I recall correctly there was a time when M$ compilers didn't implement the string class completely

Such a lack in the implementation could be hard to believe, though :)

Anyway, here's my homemade string class. It is a lot safer than std::string, but it misses a few features that would make it complete:

Code:

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class String
{
    public:
    unsigned capacity() const { return 0; }
    bool empty() const { return true; }
    unsigned find( const String& str, unsigned index ) const { return std::numeric_limits<unsigned>::max(); }
    unsigned size() const { return 0; }
    //TO_DO: add other methods
};

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Quote:

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Originally Posted by pantherse

Looks like they learned C++ using Visual Studio 7 or something. If I recall correctly there was a time when M$ compilers didn't implement the string class completely

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Well the std::string in VC++ 6.0 seems fairly correct. I haven't used anything earlier than that.

Quote:

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Originally Posted by anon

Such a lack in the implementation could be hard to believe, though :)

Anyway, here's my homemade string class. It is a lot safer than std::string, but it misses a few features that would make it complete:

Code:

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class String
{
    public:
    unsigned capacity() const { return 0; }
    bool empty() const { return true; }
    unsigned find( const String& str, unsigned index ) const { return std::numeric_limits<unsigned>::max(); }
    unsigned size() const { return 0; }
    //TO_DO: add other methods
};

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LOL!

Quote:

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Anyway, here's my homemade string class. It is a lot safer than std::string, but it misses a few features that would make it complete

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I thought the std::string is pretty safe?...

There are some problems because it has to interface with C-style strings. E.g

Code:

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std::string s(0);

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I'm not sure if this is required to throw an exception.

Quote:

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I'm not sure if this is required to throw an exception.

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It is not allowed by the pre-condition, but the behaviour is undefined.