std::vector<std::string> vec;

vec.emplace_back( "sse" );
vec.emplace_back( "avx" );
vec.emplace_back( "generic" );

vec.erase( std::remove( vec.begin(), vec.end(), "sse" ), vec.end() );

auto it = remove(...);
if (it == vec.end())
{
    // Не удалено
}
else
{
    vec.erase(it,vec.end());
}

auto save = vec.size();
vec.erase( std::remove( vec.begin(), vec.end(), "sse" ), vec.end() );
if (vec.size() == save)
{
    // Ничего не удалено
}

vector<string> vec{ "sse", "avx", "generic" };
if (auto it = remove(vec.begin(),vec.end(),"sse"); it != vec.end())
{
    vec.erase(it,vec.end());
    cout << "removed!n";
}
else
{
    cout << "Not foundn";
}

const std::string s = "sse";
auto first = std::remove( vec.begin(), vec.end(), s ), last = vec.end();
if (bool removed = last - first)  // ваш ответ
     vec.erase(first , last);