这是我用来在我的程序中这样做的代码…这没什么特别的，但很管用……注意，您必须根据需要调整您的尺寸。我的MAX_BUFFER是1024。

std::string Format ( const char *fmt, ... )
{
    char textString[MAX_BUFFER*5] = {'\0'};

    // -- Empty the buffer properly to ensure no leaks.
    memset(textString, '\0', sizeof(textString));

    va_list args;
    va_start ( args, fmt );
    vsnprintf ( textString, MAX_BUFFER*5, fmt, args );
    va_end ( args );
    std::string retStr = textString;
    return retStr;
}

这是我用来在我的程序中这样做的代码…这没什么特别的，但很管用……注意，您必须根据需要调整您的尺寸。我的MAX_BUFFER是1024。

std::string Format ( const char *fmt, ... )
{
    char textString[MAX_BUFFER*5] = {'\0'};

    // -- Empty the buffer properly to ensure no leaks.
    memset(textString, '\0', sizeof(textString));

    va_list args;
    va_start ( args, fmt );
    vsnprintf ( textString, MAX_BUFFER*5, fmt, args );
    va_end ( args );
    std::string retStr = textString;
    return retStr;
}

Poco Foundation库有一个非常方便的格式函数，它在格式字符串和值中都支持std::string:

道格:http://pocoproject.org/docs/Poco.html # 7308 来源:https://github.com/pocoproject/poco/blob/develop/Foundation/src/Format.cpp

到目前为止，所有的答案似乎都有一个或多个这样的问题:(1)它可能无法在vc++上工作(2)它需要额外的依赖，如boost或fmt(3)它太复杂的自定义实现，可能没有经过很好的测试。

下面的代码解决了上述所有问题。

#include <string>
#include <cstdarg>
#include <memory>

std::string stringf(const char* format, ...)
{
    va_list args;
    va_start(args, format);
    #ifndef _MSC_VER

        //GCC generates warning for valid use of snprintf to get
        //size of result string. We suppress warning with below macro.
        #ifdef __GNUC__
        #pragma GCC diagnostic push
        #pragma GCC diagnostic ignored "-Wformat-nonliteral"
        #endif

        size_t size = std::snprintf(nullptr, 0, format, args) + 1; // Extra space for '\0'

        #ifdef __GNUC__
        # pragma GCC diagnostic pop
        #endif

        std::unique_ptr<char[]> buf(new char[ size ] ); 
        std::vsnprintf(buf.get(), size, format, args);
        return std::string(buf.get(), buf.get() + size - 1 ); // We don't want the '\0' inside
    #else
        int size = _vscprintf(format, args);
        std::string result(++size, 0);
        vsnprintf_s((char*)result.data(), size, _TRUNCATE, format, args);
        return result;
    #endif
    va_end(args);
}    

int main() {
    float f = 3.f;
    int i = 5;
    std::string s = "hello!";
    auto rs = stringf("i=%d, f=%f, s=%s", i, f, s.c_str());
    printf("%s", rs.c_str());
    return 0;
}

注:

Separate VC++ code branch is necessary because VC++ has decided to deprecate snprintf which will generate compiler warnings for other highly voted answers above. As I always run in "warnings as errors" mode, its no go for me. The function accepts char * instead of std::string. This because most of the time this function would be called with literal string which is indeed char *, not std::string. In case you do have std::string as format parameter, then just call .c_str(). Name of the function is stringf instead of things like string_format to keepup with printf, scanf etc. It doesn't address safety issue (i.e. bad parameters can potentially cause seg fault instead of exception). If you need this then you are better off with boost or fmt libraries. My preference here would be fmt because it is just one header and source file to drop in the project while having less weird formatting syntax than boost. However both are non-compatible with printf format strings so below is still useful in that case. The stringf code passes through GCC strict mode compilation. This requires extra #pragma macros to suppress false positives in GCC warnings.

以上代码已在，

GCC 4.9.2 11 / c++ / C + + 14 vc++编译器19.0 铿锵声3.7.0

c++ 20 std::格式

它来了!该特性描述在:http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0645r9.html，并使用类似python的.format()语法。

我希望它的用法是这样的:

#include <format>
#include <string>

int main() {
    std::string message = std::format("The answer is {}.", 42);
}

g++-9 -std=c++2a的GCC 9.1.0仍然不支持它。

现有的fmt库在获得官方支持之前实现了它:https://github.com/fmtlib/fmt，如前所述:std::string格式化，如sprintf:

sudo apt install libfmt-dev

修改源代码以替换:

用<fmt/core.h> .h格式化> Std::format转换为fmt::format

main.cpp

#include <string>
#include <iostream>

#include <fmt/core.h>

int main() {
    std::string message = fmt::format("The answer is {}.", 42);
    std::cout << message << std::endl;
}

编译并运行:

g++ -std=c++11 -o main.out main.cpp -lfmt
./main.out

输出:

The answer is 42.

API将添加一个新的std::format头文件:

建议的格式化API定义在新的header <format>中，应该不会对现有代码产生影响。

十六进制格式{:x}

c++十六进制成本值？

前导零{:03}

用c++输出操作符打印前导零?

左对齐{:<}，右对齐{:>}，中对齐{:^}

打印cout时c++对齐<<

浮点精度{:.2}

我如何打印一个双值与全精度使用cout? 在c++中设置默认浮点打印精度

在正数{:+}上显示符号

如何打印正数与前缀+在c++

将布尔值显示为true和false: {:}

在c++中将bool转换为文本

你不能直接这样做，因为你没有对底层缓冲区的写访问权(直到c++ 11;见Dietrich Epp的评论)。你必须先在c-string中执行，然后将其复制到std::string中:

  char buff[100];
  snprintf(buff, sizeof(buff), "%s", "Hello");
  std::string buffAsStdStr = buff;

但我不确定为什么不直接使用字符串流?我想你有特定的理由不这么做:

  std::ostringstream stringStream;
  stringStream << "Hello";
  std::string copyOfStr = stringStream.str();