c++ - 从 'char'到 'const char*'的无效转换

我有一个程序，使用randomCharacter函数生成一个随机字符，并使用randomString函数生成随机字符串。后者利用前者，breedWithMutation使用randomCharacter概率性地突变基因序列的表示。

#include <ctime>
#include <boost/random.hpp>

typedef boost::mt19937 randAlgorithm;

int mutationsPerGeneration = 100;
double probabilityOfMutation = 0.05;
string potentialAlleles = "abcdefghijklmnopqrstuvwxyz ";
size_t numberOfAlleles = potentialAlleles.size();

double random01(randAlgorithm & engine)
{
  boost::uniform_real<double> u01;
  return u01(engine);
}

int randomInteger(randAlgorithm & engine, size_t min, size_t max) {
  boost::uniform_int<> minmax(min, max);
  return minmax(engine);
}

string randomCharacter(randAlgorithm & engine, string charSet, size_t charSetSize) {
  return charSet[randomInteger(engine, 0, charSetSize)];
}

string randomString(randAlgorithm & engine, size_t length, string charSet, size_t charSetSize) {
  string s;
  s.reserve(length);
  for (int i = 0; i < length; i++) {
    s.append(randomCharacter(engine, charSet, charSetSize));
  }
  return s;
}

string breedWithMutation(randAlgorithm & engine, string originalGenome, size_t genomeSize) {
  string mutatedGenome;
  mutatedGenome.reserve(genomeSize);
  double mutationDraw;
  for (size_t i = 0; i < genomeSize; i++) {
    mutationDraw = random01(engine);
    if (mutationDraw < probabilityOfMutation) { //The allele undergoes mutation
      mutatedGenome.append(randomCharacter(engine, potentialAlleles, numberOfAlleles));
    }
    else {
      mutatedGenome.append(originalGenome[i]);
    }
  }
  return mutatedGenome;
}

但是，在构建应用程序时，出现以下错误:

    main.cpp: In function ‘std::string randomCharacter(randAlgorithm&, std::string, size_t)’:
main.cpp:31:55: error: invalid conversion from ‘char’ to ‘const char*’
main.cpp:31:55: error:   initializing argument 1 of ‘std::basic_string<_CharT, _Traits, _Alloc>::basic_string(const _CharT*, const _Alloc&) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>]’
main.cpp: In function ‘std::string breedWithMutation(randAlgorithm&, std::string, size_t)’:
main.cpp:53:45: error: invalid conversion from ‘char’ to ‘const char*’
main.cpp:53:45: error:   initializing argument 1 of ‘std::basic_string<_CharT, _Traits, _Alloc>& std::basic_string<_CharT, _Traits, _Alloc>::append(const _CharT*) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>, std::basic_string<_CharT, _Traits, _Alloc> = std::basic_string<char>]’

我意识到，错误中的行号排列不完全，但是前两个错误是randomCharacter中的唯一一行，而第三个和第四个错误是此行:mutatedGenome.append(originalGenome[i]);中的breedWithMutation。是什么导致此错误？

最佳答案

在C++中，char和string是截然不同的类型。不能将char值隐式转换为string(就像您尝试在randomCharacter中那样)。

您可以将randomCharacter的返回类型更改为char而不是string，尽管这也可能需要在其他地方进行更改(我没有详细检查您的代码)。

关于c++ - 从 'char'到 'const char*'的无效转换，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/8291007/